RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1

RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1

These Solutions are part of RD Sharma Class 10 Solutions. Here we have given RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1

Other Exercises

Question 1.
In each of the following, one of the six trigonometric ratios is given. Find the values of the other trigonometric ratios.
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 1
Solution:
∴ Perpendicular BC – 2 units and
Hypotenuse AC = 3 units
By Phythagoras Theorem, in AABC,
(Hypotenuse)2 = (Base)2 + (Perpendicular)2
AC2 = AB2 + BC2
⇒ (3)2 = (AB)2 + (2)2
⇒ 9 = AB2 + 4 ⇒ AB2 = 9-4 = 5
AB = √5 units
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 2
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 3
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 4
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RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 19
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 20

Question 2.
In a ΔABC, right angled at B, AB = 24 cm, BC = 7 cm. Determine
(i) sin A, cos A
(ii) sin C, cos C.

Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 21

Question 3.
In the figure, find tan P and cot R. Is tan P = cot R ?
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 22
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 23

Question 4.
If sin A = \(\frac { 9 }{ 41 }\), compute cos A and tan A.
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 24

Question 5.
Given 15 cot A = 8, find sin A and sec A.
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 25

Question 6.
In ΔPQR, right angled at Q, PQ = 4 cm and RQ = 3 cm. Find the values of sin P, sin R, sec P and sec R.
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 26
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 27

Question 7.
If cot 0 = \(\frac { 7 }{ 8 }\), evaluate :
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 28
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 29
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 30
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 31

Question 8.
If 3 cot A = 4, check whether \(\frac { 1-{ tan }^{ 2 }A }{ 1+{ tan }^{ 2 }A }\) = cos2 A – sin2 A or not.
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 32
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 33

Question 9.
If tan θ = a/b , Find the Value of \(\frac { cos\theta +sin\theta }{ cos\theta -sin\theta }\).
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 34
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 35

Question 10.
If 3 tan θ = 4, find the value of 4cos θ – sin θ \(\frac { 4cos\theta -sin\theta }{ 2cos\theta +sin\theta }\).
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 36
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 37

Question 11.
If 3 cot 0 = 2, find the value of \(\frac { 4sins\theta -3cos\theta }{ 2sin\theta +6cos\theta }\).
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 38

Question 12.
If tan θ = \(\frac { a }{ b }\), prove that
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 39
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 40

Question 13.
If sec θ = \(\frac { 13 }{ 5 }\), show that \(\frac { 2sins\theta -3cos\theta }{ 4sin\theta -9cos\theta }\) =3.
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 41

Question 14.
If cos θ \(\frac { 12 }{ 13 }\), show that sin θ (1 – tan θ) \(\frac { 35 }{ 156 }\).
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 42
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 43

Question 15.
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 44
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 45
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 46

Question 16.
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 47
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 48
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 49

Question 17.
If sec θ = \(\frac { 5 }{ 4 }\), find the value of \(\frac { sins\theta -2cos\theta }{ tan\theta -cot\theta }\).
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 50
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 51

Question 18.
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 52
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 53
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 54

Question 19.
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 55
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 56
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 57

Question 20.
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 58
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 59
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 60

Question 21.
If tan θ = \(\frac { 24 }{ 7 }\), find that sin θ + cos θ.
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 61
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 62

Question 22.
If sin θ = \(\frac { a }{ b }\), find sec θ + tan θ in terms of a and b.
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 63

Question 23.
If 8 tan A = 15, find sin A – cos A.
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 64

Question 24.
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 65
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 66
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 67

Question 25.
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 68
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 69
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 70

Question 26.
If ∠A and ∠B are acute angles such that cos A = cos B, then show that ∠A = ∠B.
Solution:
∠A and ∠B are acute angles and cos A = cos B
Draw a right angle AABC, in which ∠C – 90°
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 71

Question 27.
In a ∆ABC, right angled at A, if tan C =√3 , find the value of sin B cos C + cos B sin C. (C.B.S.E. 2008)
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 72
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 73

Question 28.
28. State whether the following are true or false. Justify your answer.
(i) The value of tan A is always less than 1.
(ii) sec A = \(\frac { 12 }{ 5 }\) for some value of angle A.
(iii) cos A is the abbreviation used for the cosecant of angle A.
(iv) cot A is the product of cot and A.
(v) sin θ = \(\frac { 4 }{ 3 }\) for some angle θ.
Solution:
(i) False, value of tan A 0 to infinity.
(ii) True.
(iii) False, cos A is the abbreviation of cosine A.
(iv) False, it is the cotengent of angle A.
(v) Flase, value of sin θ varies on 0 to 1.

Question 29.
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 74
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 75
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 76
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 77

Question 30.
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 78
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 79
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 80

Question 31.
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 81
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 82
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 83

Question 32.
If sin θ =\(\frac { 3 }{ 4 }\), prove that
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 84
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 85
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 86

Question 33.
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 87
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 88
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 89

Question 34.
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 90
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 91
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 92
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 93

Question 35.
If 3 cos θ-4 sin θ = 2 cos θ + sin θ, find tan θ.
Solution:
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 94

Question 36.
If ∠A and ∠P are acute angles such that tan A = tan P, then show that ∠A = ∠P.
Solution:
∠A and ∠P are acute angles and tan A = tan P Draw a right angled AAPB in which ∠B = 90°
RD Sharma Class 10 Solutions Chapter 10 Trigonometric Ratios Ex 10.1 95

 

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RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2

RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2

These Solutions are part of RD Sharma Class 10 Solutions. Here we have given RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2

Other Exercises

Question 1.
Find the distance between the following pair of points :
(i) (-6, 7) and (-1, -5)
(ii) (a + b, b + c) and (a – b, c – b)
(iii) (a sin α, -b cos α) and (-a cos α, -b sin α)
(iv) (a, 0) and (0, b)
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 1
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 2
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 3

Question 2.
Find the value of a when the distance between the points (3, a) and (4, 1) is √10
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 4
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 5

Question 3.
If the points (2, 1) and (1, -2) are equidistant from the point (x, y), show that x + 3y = 0.
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 6

Question 4.
Find the values of x, y if the distances of the point (x, y) from (-3, 0) as well as from (3, 0) are 4.
Solution:
Distance between (x, y) and (-3, 0) is
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 7
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 8

Question 5.
The length of a line segment is of 10 units and the coordinates of one end-point are (2, -3). If the abscissa of the other end is 10, find the ordinate of the other end.
Solution:
Let the ordinate of other end by y, then The distance between (2, -3) and (10, y) is
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 9
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 10

Question 6.
Show that the points (-4, -1), (-2, -4), (4, 0) and (2, 3) are the vertices points of a rectangle. (C.B.S.E. 2006C)
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 11
AB = CD and AD = BC
and diagonal AC = BD
ABCD is a rectangle

Question 7.
Show that the points A (1, -2), B (3, 6), C (5, 10) and D (3, 2) are the vertices of a parallelogram.
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 12

Question 8.
Prove that the points A (1, 7), B (4, 2), C (-1, -1) and D (-4, 4) are the vertices of a square. [NCERT]
Solution:
Vertices A (1, 7), B (4, 2), C (-1,-1), D (-4, 4)
If these are the vertices of a square, then its diagonals and sides are equal
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 13
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 14

Question 9.
Prove that the points (3, 0), (6, 4) and (-1, 3) are the vertices of a right-angled isosceles triangle. (C.B.S.E. 2006C)
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 15
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 16

Question 10.
Prove that (2, -2), (-2, 1) and (5, 2) are the vertices of a right angled triangle. Find the area of the triangle and the length of the hypotenuse.
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 17
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 18

Question 11.
Prove that the points (2a, 4a), (2a, 6a) and (2a + √3 a , 5a) are the vertices of an equilateral triangle.
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 19

Question 12.
Prove that the points (2, 3), (-4, -6) and (1, \(\frac { 3 }{ 2 }\) )do not form a triangle.
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 20
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 21

Question 13.
The points A (2, 9), B (a, 5) and C (5, 5) are the vertices of a triangle ABC right angled at B. Find the values of a and hence the area of ∆ABC. [NCERT Exemplar]
Solution:
Given that, the points A (2, 9), B (a, 5) and C (5, 5) are the vertices of a ∆ABC right angled at B.
By Pythagoras theorem, AC² = AB² + BC² ………(i)
Now, by distance formula,
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 22
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 23

Question 14.
Show that the quadrilateral whose vertices are (2, -1), (3, 4), (-2, 3) and (-3, -2) is a rhombus.
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 24
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 25

Question 15.
Two vertices of an isosceles triangle are (2, 0) and (2, 5). Find the third vertex if the length of the equal sides is 3.
Solution:
Two vertices of an isosceles ∆ABC are A (2, 0) and B (2, 5). Let co-ordinates of third vertex C be (x, y)
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 26
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 27
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 28
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 29

Question 16.
Which point on x-axis is equidistant from (5, 9) and (-4, 6) ?
Solution:
Let co-ordinates of two points are A (5, 9), B (-4, 6)
The required point is on x-axis
Its ordinates or y-co-ordinates will be 0
Let the co-ordinates of the point C be (x, 0)
AC = CB
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 30
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 31

Question 17.
Prove that the point (-2, 5), (0, 1) and (2, -3) are collinear.
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 32
Now AB + BC = 2√5 +2√5
and CA = 4√5
AB + BC = CA
A, B and C are collinear

Question 18.
The co-ordinates of the point P are (-3,2). Find the co-ordinates of the point Q which lies on the line joining P and origin such that OP = OQ.
Solution:
Co-ordinates of P are (-3, 2) and origin O are (0, 0)
Let co-ordinates of Q be (x, y)
O is the mid point of PQ
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 33
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 34
= 9 + 4 = (±3)² + (±2)²
The point will be in fourth quadrant
Its y-coordinates will be negative
and x-coordinates will be positive
Now comparing the equation
x² = (±3)² => x = ±3
y² = (±2)² => y = ±2
x = 3, y = -2
Co-ordinates of the point Q are (3, -2)

Question 19.
Which point on y-axis is equidistant from (2, 3) and (-4, 1) ?
Solution:
The required point lies on y-axis
Its abscissa will be zero
Let the point be C (0, y) and A (2, 3), B (-4, 1)
Now,
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 35

Question 20.
The three vertices of a parallelogram are (3, 4), (3, 8) and (9, 8). Find the fourth vertex.
Solution:
Let ABCD be a parallelogram and vertices will be A (3, 4), B (3, 8), C (9, 8)
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 36
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 37
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 38
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 39

Question 21.
Find a point which is equidistant from the point A (-5, 4) and B (-1, 6). How many such points are there? [NCERT Exemplar]
Solution:
Let P (h, k) be the point which is equidistant from the points A (-5, 4) and B (-1, 6).
PA = PB
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 40
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 41
So, the mid-point of AB satisfy the Eq. (i).
Hence, infinite number of points, in fact all points which are solution of the equation 2h + k + 1 = 0, are equidistant from the point A and B.
Replacing h, k, by x, y in above equation, we have 2x + y + 1 = 0

Question 22.
The centre of a circle is (2a, a – 7). Find the values of a if the circle passes through the point (11, -9) and has diameter 10√2 units. [NCERT Exemplar]
Solution:
By given condition,
Distance between the centre C (2a, a-1) and the point P (11, -9), which lie on the circle = Radius of circle
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 42
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 43

Question 23.
Ayush starts walking from his house to office. Instead of going to the office directly, he goes to a bank first, from there to his daughter’s school and then reaches the office. What is the extra distance travelled by Ayush in reaching the office? (Assume that all distance covered are in straight lines). If the house is situated at (2, 4), bank at (5, 8), school at (13, 14) and office at (13, 26) and coordinates are in kilometers. [NCERT Exemplar]
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 44
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 45
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 46

Question 24.
Find the value of k, if the point P (0, 2) is equidistant from (3, k) and (k, 5).
Solution:
Let P (0, 2) is equidistant from A (3, k) and B (k, 5)
PA = PB
=> PA² = PB²
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 47

Question 25.
If (-4, 3) and (4, 3) are two vertices of an equilateral triangle, find the coordinates of the third vertex, given that the origin lies in the
(i) interior,
(ii) exterior of the triangle. [NCERT Exemplar]
Solution:
Let the third vertex of an equilateral triangle be (x, y).
Let A (-4, 3), B (4,3) and C (x, y).
We know that, in equilateral triangle the angle between two adjacent side is 60 and all three sides are equal.
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 48
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 49
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 50
But given that, the origin lies in the interior of the ∆ABC and the x-coordinate of third vertex is zero.
Then, y-coordinate of third vertex should be negative.
Hence, the require coordinate of third vertex,
C = (0, 3 – 4√3). [C ≠ (0, 3 + 4√3)]

Question 26.
Show that the points (-3, 2), (-5, -5), (2, -3) and (4, 4) are the vertices of a rhombus. Find the area of this rhombus.
Solution:
Let the co-ordinates of the vertices A, B, C and D of a rhombus are A (-3, 2), B (-5, -5), C (2, -3) and D (4, 4)
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 51
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 52

Question 27.
Find the coordinates of the circumcentre of the triangle whose vertices are (3, 0), (-1, -6) and (4, -1). Also, find its circumradius.
Solution:
Let ABC is a triangle whose vertices are A (3, 0), B (-1, -6) and C (4, -1)
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 53
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 54

Question 28.
Find a point on the x-axis which is equidistant from the points (7, 6) and (-3, 4). [CBSE 2005]
Solution:
The required point is on x-axis
Its ordinate will be O
Let the co-ordinates of the required point P (x, 0)
Let the point P is equidistant from the points A (7, 6) and B (-3, 4)
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 55
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 56

Question 29.
(i) Show that the points A (5, 6), B (1, 5), C (2, 1) and D (6, 2) are the vertices of a square. [CBSE 2004]
(ii) Prove that the points A (2, 3), B (-2, 2), C (-1, -2) and D (3, -1) are the vertices of a square ABCD. [CBSE 2013]
(iii) Name the type of triangle PQR formed by the point P(√2 , √2), Q(- √2, – √2) and R (-√6 , √6 ). [NCERT Exemplar]
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 57
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 58
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 59
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 60

Question 30.
Find the point on x-axis which is equidistant from the points (-2, 5) and (2, -3). [CBSE 2004]
Solution:
The point P lies on x-axis
The ordinates of P will be 0 Let the point P be (x, 0)
Let P is equidistant from A (-2, 5) and B (2, -3)
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 61
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 62

Question 31.
Find the value of x such that PQ = QR where the co-ordinates of P, Q and R are (6, -1) (1, 3) and (x, 8) respectively. [CBSE 2005]
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 63

Question 32.
Prove that the points (0, 0), (5, 5) and (-5, 5) are the vertices of a right isosceles triangle. [CBSE 2005]
Solution:
Let the vertices of a triangle be A (0, 0), B (5, 5) and C (-5, 5)
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 64
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 65

Question 33.
If the points P (x, y) is equidistant from the points A (5, 1) and B (1,5), prove that x = y. [CBSE 2005]
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 66

Question 34.
If Q (0, 1) is equidistant from P (5, -3) and R (x, 6) find the values of x. Also find the distances QR and PR. [NCERT]
Solution:
Q (0, 1) is equidistant from P (5, -3) and R (x, 6)
PQ = RQ
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 67
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 68

Question 35.
Find the values ofy for which the distance between the points P (2, -3) and Q (10, y) is 10 units. [NCERT]
Solution:
Distance between P (2, -3) and Q (10, y) = 10
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 69

Question 36.
If the point P (k – 1, 2) is equidistant from the points A (3, k) and B (k, 5), find the values of k. [CBSE 2014]
Solution:
Point P (k – 1, 2) is equidistant from A (3, k) and B (k, 5)
PA= PB
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 70

Question 37.
If the point A (0, 2) is equidistant from the point B (3, p) and C (p, 5), find p. Also, find the length of AB. [CBSE 2014]
Solution:
Point A (0, 2) is equidistant from B (3, p) and C (p, 5)
AB = AC
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 71

Question 38.
Name the quadrilateral formed, if any, by the following points, and give reasons for your answers :
(i) A (-1, -2), B (1, 0), C (-1, 2), D (-3, 0)
(ii) A (-3, 5), B (3, 1), C (0, 3), D (-1, -4)
(iii) A (4, 5), B (7, 6), C (4, 3), D (1, 2)
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 72
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 73
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 74
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 75

Question 39.
Find the equation of the perpendicular bisector of the line segment joining points (7, 1) and (3, 5).
Solution:
Let the given points are A (7, 1) and B (3, 5) and mid point be M
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 76
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 77

Question 40.
Prove that the points (3, 0), (4, 5), (-1, 4) and (-2, -1) taken in order, form a rhombus. Also find its area.
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 78
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 79

Question 41.
In the seating arrangement of desks in a classroom three students Rohini, Sandhya and Bina are seated at A (3, 1), B (6, 4) and C (8, 6). Do you think they are seated in a line ?
Solution:
A (3, 1), B (6, 4) and C (8, 6)
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 80

Question 42.
Find a point ony-axis which is equidistant from the points (5, -2) and (-3, 2).
Solution:
The point lies on y-axis
Its x = 0
Let the required point be (0, y) and let A (5, -2) and B (-3, 2)
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 81

Question 43.
Find a relation between x and y such that the point (x, y) is equidistant from the points (3, 6) and (-3, 4). [NCERT]
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 82

Question 44.
If a point A (0, 2) is equidistant from the points B (3, p) and C (p, 5), then find the value of p. [CBSE 2012]
Solution:
Point A (0, 2) is equidistant from the points B (3, p) and C (p, 5)
AB = AC
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 83
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 84

Question 45.
Prove that the points (7, 10), (-2, 5) and (3, -4) are the vertices of an isosceles right triangle. [CBSE 2013]
Solution:
Let points are A (7, 10), B (-2, 5) and C (3, -4)
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 85

Question 46.
If the point P (x, 3) is equidistant from the points A (7, -1) and B (6, 8), find the value of x and And the distance AP. [CBSE 2014]
Solution:
Point P (x, 3) is equidistant from the points A (7, -1) and B (6, 8)
PA = PB
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 86
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 87

Question 47.
If A (3, y) is equidistant from points P (8, -3) and Q (7, 6), find the value of y and find the distance AQ. [CBSE 2014]
Solution:
Point A (3, y) is equidistant from P (8, -3) and Q (7, 6)
i.e., AP = AQ
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 88

Question 48.
If (0, -3) and (0, 3) are the two vertices of an equilateral triangle, find the coordinates of its third vertex. [CBSE 2014]
Solution:
Let A (0, -3) and B (0, 3) are vertices of an equilateral triangle
Let the coordinates of the third vertex be C (x, y)
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 89
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 90

Question 49.
If the point P (2, 2) is equidistant from the points A (-2, k) and B (-2k, -3), find k. Also, find the length of AP.
Solution:
Point P (2, 2) is equidistant from the points A (-2, k) and B (-2k, -3)
AP = BP
Now,
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 91
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 92

Question 50.
Show that ∆ABC, where A (-2, 0), B (2, 0), C (0, 2) and ∆PQR, where P (-4, 0), Q (4, 0), R (0, 4) are similar.
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 93
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 94
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 95

Question 51.
An equilateral triangle has two vertices at the points (3, 4), and (-2, 3). Find the co-ordinates of the third vertex.
Solution:
Let two vertices of an equilateral triangle are A (3,4), and B (-2,3) and let the third vertex be C (x, y)
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 96
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 97
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 98
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 99

Question 52.
Find the circumcentre of the triangle whose vertices are (-2, -3), (-1, 0), (7, -6).
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 100
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 101
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 102

Question 53.
Find the angle subtended at the origin by the line segment whose end points are (0, 100) and (10, 0).
Solution:
Let co-ordinates of the end points of a line segment are A (0, 100), B (10, 0) and origin is O (0, 0)
Abscissa of A is 0
It lies on y-axis
Similarly, ordinates of B is 0
It lies on x-axis
But axes intersect each other at right angle
AB will subtended 90° at the origin
Angle is 90° or \(\frac { \pi }{ 2 }\)

Question 54.
Find the centre of the circle passing through (5, -8), (2, -9) and (2, 1).
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 103
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 104
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 105

Question 55.
If two opposite vertices of a square are (5, 4) and (1, -6), find the coordinates of its remaining two vertices.
Solution:
Two opposite points of a square are (5, 4) and (1, -6)
Let ABCD be a square and A (5, 4) and C (1, -6) are the opposite points
Let the co-ordinates of B be (x, y). Join AC
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 106
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 107
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 108

Question 56.
Find the centre of the circle passing through (6, -6), (3, -7) and (3, 3).
Solution:
Let O is the centre of the circle is (x, 7) Join OA, OB and OC
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 109
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 110

Question 57.
Two opposite vertices of a square are (-1, 2) and (3, 2). Find the co-ordinates of other two vertices.
Solution:
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 111
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 112
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 113

Hope given RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.2 are helpful to complete your math homework.

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RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2

RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2

These Solutions are part of RD Sharma Class 10 Solutions. Here we have given RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2

Other Exercises

Question 1.
Find, in terms of π the length of the arc that subtends an angle of 30° at the centre of a circle of radius 4 cm.
Solution:
Radius of the circle (r) = 4 cm
Angle at the centre subtended an arc = 30°
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 1

Question 2.
Find the angle subtended at the centre of a circle of radius 5 cm by an arc of length \((\frac { 5\pi }{ 3 } \) cm.
Solution:
Radius of the circle (r) = 5 cm 571
Length of arc = \(\frac { 5\pi }{ 3 }\) cm
Let θ be the angle subtended by the arc, then
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 2

Question 3.
An arc of length 20tc cm subtends an angle of 144° at the centre of a circle. Find the radius of the circle.
Solution:
Length of an arc = 20π cm
Angle subtended by the arc = 144°
Let r be the radius of the circle, then
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 3

Question 4.
An arc of length 15 cm subtends an angle of 45° at the centre of a circle. Find in terms of π ; the radius of the circle.
Solution:
Length of arc = 15 cm
Angle subtended at the centre = 45°
Let r be the radius of the circle, then
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 4
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 5

Question 5.
Find the angle subtended at the centre of a circle of radius ‘a’  by an arc of length \((\frac { a\pi }{ 4 } )\)  cm.
Solution:
Radius of the circle (r) = a cm
Length of arc = \(\frac { a\pi }{ 4 }\)   cm
Let θ be the angle subtended by the arc at the centre, then
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 6

Question 6.
A sector of a circle of radius 4 cm contains an angle of 30°. Find the area of the sector.
Solution:
Radius of the sector of a circle (r) = 4 cm
Angle at the centre (θ) = 30°
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 7
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 8

Question 7.
A sector of a circle of radius 8 cm contains an angle of 135°. Find the area of the sector.
Solution:
Radius of the sector of the circle (r) = 8 cm
Angle at the centre (θ) = 135°
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 9

Question 8.
The area of a sector of a circle of radius 2 cm is 7 is cm2. Find the angle contained by the sector.
Solution:
Area of the sector of a circle =π cm2
Radius of the circle (r) = 2 cm
Let 0 be the angle at the centre, then
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 10

Question 9.
The area of a sector of a circle of radius 5 cm is 5π cm2. Find the angle contained by the sector.
Solution:
Area of the sector of a circle = 5π cm2
Radius of the circle (r) = 5 cm
Let 9 be the angle at the centre, then
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 11

Question 10.
Find the area of the sector of a circle of radius 5 cm, if the corresponding arc length is 3.5 cm. [NCERT Exemplar]
Solution:
Let the central angle of the sector be θ.
Given that, radius of the sector of a circle (r) = 5 cm
and arc length (l) = 3.5 cm
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 12
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 13

Question 11.
In a circle of radius 35 cm, an arc subtends an angle of 72° at the centre. Find the length of the arc and area of the sector.
Solution:
Radius of the circle (r) = 25 cm
Angle at the centre (θ) = 72°
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 14

Question 12.
The perimeter of a sector of a circle of radius 5.7 m is 27.2 m. Find the area of the sector.
Solution:
Radius of the circle (r) = 5.7 m
Perimeter of the sector = 27.2 m
Length of the arc = Perimeter – 2r
= (27.2 – 2 x 5.7) m
= 27.2 – 11.4 = 15.8 m
Let θ be the central angle, then
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 15
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 16

Question 13.
The perimeter of a certain sector of a circle of radius 5.6 cm is 27.2 m. Find the area of the sector.
Solution:
Radius of the sector (r) = 5.6 cm
and perimeter of the sector = 27.2 cm
∴ Length of arc = Perimeter – 2r
= 27.2 – 2 x 5.6
= 27.2- 11.2= 16.0 cm
∴ θ be the angle at the centre, then
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 17

Question 14.
A sector is cut-off from a circle of radius 21 cm. The angle of the sector is 120°. Find the length of its arc and the area.
Solution:
Radius of the sector of a circle (r) = 21 cm
Angle at the centre = 120°
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 18

Question 15.
The minute hand of a clock is \(\sqrt { 21 } \)  cm long, Find the area described by the minute hand on the face of the clock between 7.00 A.M. and 7.05 A.M.
Solution:
Length of minute hand of a clock (r) = \(\sqrt { 21 }\)  cm
Period = 7 a.m. to 7.05 a.m. 5 minutes
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 19

Question 16.
The minute hand of a clock is 10 cm long. Find the area of the face of the clock described by the minute hand between 8.00 A.M. and 8.25 A.M.
Solution:
Length of minute hand of a clock (r) = 10 cm
Period = 8 A.M. to 8.25 A.M. = 25 minutes
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 20

Question 17.
The sector of 56° cut out from a circle contains area 4.4 cm2, Find the radius of the circle.
Solution:
Area of a sector = 4.4 cm2
Central angle = 56°                                        ‘
Let r be the radius of the sector of the circle, then
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 21

Question 18.
Area of a sector of central angle 200° of a circle s 770²cm. Find the length of the corresponding are of this sector.
Solution:
Let the radius of the sector AOBA be r.
Given that, Central angle of sector AOBA = θ = 200°
and area of the sector AOBA = 770 cm2
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 22
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 23

Question 19.
The length of minute hand of a clock is 5 cm. Find the area swept by the minute hand during the time period 6:05 am and 6:40 am.           [NCERT Exemplar]
Solution:
We know that, in 60 min, minute hand revolving = 360°
In 1 min, minute hand revolving = \(\frac { 360\circ }{ 60\circ }\)

RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 24
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 25

Question 20.
The length of the minute hand of a clock is 14 cm. Find the area swept by the minute hand in 5 minutes. [CBSE 2013]
Solution:
Length of minute hand (r)= 14 cm
Area swept by the minute hand in 5 minutes
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 26

Question 21.
In a circle of radius 21 cm, an arc subtends an angle of 60° at the centre. Find (0 the length of the arc (ii) area of the secter formed by the arc. (Use π = 22/7) [CBSE 2013]
Solution:
Radius of a circle (r) = 21 cm
Angle at the centre = 60°
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 27

Question 22.
From a circular piece of cardboard of radius 3 cm two sectors of 90° have been cut off. Find the perimeter of the remaining portion nearest hundredth centimeters (Take π = 22/7).
Solution:
Radius of the circular piece of cardboard (r) = 3 cm
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 28
∴ Two sectors of 90° each have been cut off
∴ We get a semicular cardboard piece
∴ Perimeter of arc ACB
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 29

Question 23.
The area of a sector is one-twelfth that of the complete circle. Find the angle of the sector.
Solution:
Let r be the radius of the circle and 0 be the central angle of the sector of the circle Then area of circle = πr2

RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 30

Question 24.
AB is a chord of a circle with centre O and radius 4 cm. AB is of length 4 cm. Find the area of the sector of the circle formed by the chord AB.
Solution:
Radius of the circle with centre O (r) = 4 cm
Length of chord AB = 4 cm
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 31

Question 25.
In a circle of radius 6 cm, a chord of length 10 cm makes an angle of 110° at the centre of the circle. Find 
(i)  the circumference of the circle,
(ii) the area of the circle,
(iii) the length of the arc AB,
(iv) the area of the sector OAB.
Solution:
Radius of the circle (r) = 6 cm
Length of chord = 10 cm
and central angle (θ) =110°
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 32
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 33

Question 26.
Figure, shows a sector of a circle, centre O, containing an angle θ°. Prove that :
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 34
Solution:
Radius of the circle = r
Arc AC subtends ∠θ at the centre of the
circle. OAB is a right triangle
In the right ΔOAB,
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 35
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 36
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 37

Question 27.
Figure, shows a sector of a circle of radius r cm containing an angle θ°. The area of the sector is A cm2 and perimeter of the sector is 50 cm. Prove that
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 38
Solution:
Radius of the sector of the circle = r cm
and angle at the centre = 0
Area of sector OAB = A cm2
and perimeter of sector OAB = 50 cm
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 39
RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 40

Hope given RD Sharma Class 10 Solutions Chapter 13 Areas Related to Circles Ex 13.2 are helpful to complete your math homework.

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RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.1

RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.1

These Solutions are part of RD Sharma Class 10 Solutions. Here we have given RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.1

Other Exercises

Question 1.
On which axis do the following points lie?
(i) P (5, 0)
(ii) Q (0 – 2)
(iii) R (-4, 0)
(iv) S (0, 5)
Solution:
(i) P (5, 0)
Its ordinate or y-axis is 0. It lies on x-axis
(ii) Q (0 – 2)
Its abscissa or x-axis is 0. It lies on y-axis
(iii) R (-4, 0)
Its ordinate is 0 It lies on x-axis
(iv) S (0, 5)
Its abscissa is 0. It lies on y-axis

Question 2.
Let ABCD be a square of side 2a. Find the coordinates of the vertices of this square when
(i) A coincides with the origin and AB and AD are along OX and OY respectively.
(ii) The centre of the square is at the-origin and coordinate axes are parallel to the sides AB and AD respectively.
Solution:
ABCD is a square whose side is 2a
(i) A coincides with origin (0, 0)
AB and AD are along OX and OY respectively
Co-ordinates of A are (0, 0), of B are (2a, 0) of C are (2a, 2a) and of D are (0, 2a)
(ii) The centre of the square is at the origin (0, 0) and co-ordinates axes are parallel to the sides AB and AD respectively.
Then the co-ordinates of A are (a, a) of B are (-a, a), of C are (-a, -a) and of D are (a, -a) as shown in the figure given below :
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.1 1

Question 3.
The base PQ of two equilateral triangles PQR and PQR’ with side 2a lies along y- axis such.that the mid-point of PQ is at the origin. Find the coordinates of the vertices R and R’ of the triangles.
Solution:
∆PQR and PQR’ are equilateral triangles with side 2a each and base PQ and mid of point of PQ is 0 (0, 0) and PQ lies along y-axis
RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.1 2

 

Hope given RD Sharma Class 10 Solutions Chapter 6 Co-ordinate Geometry Ex 6.1 are helpful to complete your math homework.

If you have any doubts, please comment below. Learn Insta try to provide online math tutoring for you.

CA Foundation Business Economics Study Material – Supply

CA Foundation Business Economics Study Material Chapter 2 Theory of Demand and Supply – Supply

MEANING

Supply of a commodity refers to the quantity of commodity offered for sale at a particular price during a given period of time. Thus, the supply of a commodity may be defined as the amount of commodity which the sellers or producers are able and willing to offer for sale at a particular price, during a given period of time.

Thus, defined, the term supply shows the following features:

  1. Supply of a commodity is always with reference to a PRICE,
  2. Supply of a commodity is to be referred to IN A GIVEN PERIOD OF TIME.
  3. Supply of a commodity depends on the ABILITY OF SELLER TO SUPPLY A COMMODITY. However, ability of a seller to supply a commodity depends ON THE STOCK available with him.
  4. Supply of a commodity also depends on the WILLINGNESS OF SELLER TO SUPPLY A COMMODITY. A seller’s willingness to supply a commodity depends ON THE DIFFERENCE BETWEEN THE RESERVATION PRICE and the PREVAILING MARKET PRICE.
  5. E.g. A dairy farm’s daily supply of milk at the price of Rs. 12 per litre is 600 litres

Determinants of Supply

Supply of a commodity depends on many factors like price of the commodity, price of related goods, prices of factors of production, technology, etc. All determinants of supply can be expressed in the form of supply function as follows-
S= f(Px, Pr, Pf, T, O …….. )
Where – Sx = Quantity supplied of commodity x
f = function of (depends on)
Px = Price of commodity x
Pr = Price of related commodities
Pf = Prices of factors of production.
T = Technology
O = Objectives/Goals of the firm

Price of the commodity:

  • Other things being equal the supply of a commodity is DIRECTLY related with its price.
  • It means that, larger quantity of a commodity is offered for sale at higher price and vice versa.
  • This is because the profits of the firm increases if the price of its product increases.

Price of the related commodities:

  • The supply of a commodity also depends on the prices of related commodities i.e. substitute goods and complementary goods.
  • Other things being equal, if the price of a substitute goes up, the firms will be tempted to produce that substitute to get higher profits. E.g. – If the price of coffee rises, the firm would reduce the quantity supplied of tea.
  • On the other hand, other things being equal/if price of a complementary good goes up, the supply of the product in question also rises. E.g.- If the prices of fountain pens rise, it may cause an increase in the supply of ink.

Prices of factors of production:

  • Supply of a commodity depends on the cost of production. The cost of production itself depends upon the prices of various factors of production.
  • So, if the price of any factor of production rises, the production costs would be higher for the same level of output (and vice versa), Hence the supply will tend to decrease.
  • Conversely, a fall in the cost of production tends to increase the supply.

State of technology:

  • A change in technology affects the supply of commodity.
  • A technological progress and improvement in the methods of production increases productivity, reduce the cost of production and increases the profits. As a result more is produced and supplied.
  • Also discoveries and innovations bring new variety of goods.

Objectives of the firm:

  • The objectives of the firm and business policy pursued by it also affect the supply of the product produced by it.
  • Some firms believes in higher margin of profits and lower turnover while others believe in lower margin of profit and higher turnover (i.e. sales) to capture the market or to improve status, goodwill and prestige in the market.

Government Policy:

  • The supply of a commodity is also affected by the economic policies followed by the Government.
  • The Government may impose taxes on commodities in the form of excise duty, sales tax and import duties or may give subsidies.
  • Any increase in such taxes will raise the cost of production and so the quantity supplied will fall. Under such conditions supply will increase only when its price in the market rises.
  • Subsidies reduce the cost of production and thus encourages firms to produce and sell more.

Time:

  • Supply is a function of time also.
  • In a short period, it is not possible to adjust supply to the conditions of demand.
  • If the time period is sufficiently long, all possible adjustments can be made in the production apparatus and the supply can be fully adjusted to demand.

Number of firms:
If the number of firms producing a product increases, the market supply of the product will also increase and vice-versa.

Other factors:
Supply of a commodity also depends upon Natural conditions like rainfall, temperature, etc.; industrial and foreign policies, infrastructural facilities; War; market structure; etc.

Law of Supply

  • The Law of Supply express the nature of functional relationship between the price of a commodity and its quantity supplied.
  • It simply states that supply varies DIRECTLY to the changes in price i.e. supply of a commodity expands when price rises and contracts when price falls.
  • “The Law of Supply states that the higher the price, the greater the quantity supplied or the lower the price the smaller the quantity supplied, other things remaining the same.” (Dooley)
  • Thus, there is DIRECT RELATIONSHIP between supply and price.
  • It is assumed that other determinants of supply are constant and ONLY PRICE IS THE VARIABLE AND INFLUENCING FACTOR.

Thus, the law of supply is based on the following main assumptions:-

  • Cost of production remains unchanged even though the price of the commodity changes.
  • The technique of production remains unchanged.
  • Government policies like taxation policy, trade policy, etc. remains unchanged.
  • The prices of related goods remains unchanged.
  • The scale of production remains unchanged etc.

The law can be explained with the help of supply schedule and a corresponding supply curve.

ca-foundation-business-economics-study-material-supply-1

  • The supply schedule shows that when price rises from Rs.10 per unit to Rs. 20 per unit, the supply also rises from 20 units per week to 30 units per week and so on.
  • Thus, it shows a direct relationship between price and quantity supplied other things being equal.
  • A supply curve is the supply schedule depicted on the graph. The supply curve shows the same information as the supply schedule.

ca-foundation-business-economics-study-material-supply-2

  • In the diagram, the supply curve is sloping upwards from left to right showing a direct relationship between the price and quantity supplied.
  • A single point on supply curve show a single price supply relationship E.g. – Point ‘C’ show that if price is Rs. 30, quantity supplied is 40 units.
  • The law of supply states that, supply of a commodity varies directly with its price.

But, in some cases, this may not hold true. Hence, the law of supply has the following EXCEPTIONS.

  1. When the seller expects a further rise in the prices in future, he may hoard stock of commodity. So the supply at present will fall and vice versa.
  2. At higher wage rates, there is tendency among labourers to prefer more leisure than work. As a result when wages rise, labour supply falls.
  3. In the case of rare commodities like paintings, coins, etc. the supply is fixed. Whatever the price, it cannot change.
  4. In an auction or in all those cases where the seller wants to get rid of his goods, he will sell the goods at whatever price they fetch.

Changes in Quantity Supplied OR Expansion & Contraction of supply OR Movement along a supply curve

  • When supply of a commodity changes only due to change in the price of commodity other determinants remaining unchanged, it is called changes in quantity supplied.
  • Changes in quantity supplied thus means -expansion of supply & contraction of supply
  • When price of a commodity rises, quantity supplied also rises. This is called expansion of supply.
  • When price of a commodity falls, quantity supplied also falls. This is called contraction of supply.

As other determinants of supply like price of related commodities, prices of factors of production, state of technology, etc. are assumed to be constant, the position of the supply curve remains the same. The seller will move upwards or downwards on the same supply curve.

ca-foundation-business-economics-study-material-supply-3
In the figure above –

  • At price OP quantity supplied is OQ
  • With a rise in price to OPthe quantity supplied rises from OQ to OQ1 The co-ordinate point moves up from E to E1 This is called ‘a rise in quantity supplied’.
  • With a fall in price to OPthe quantity supplied falls from OQ to OQ2 The co-ordinate point moves down from E to E2 This is called ‘a fall in quantity supplied’.

Changes in supply OR Increase and decrease in Supply OR Shift in Supply curve

  • When there is change in supply due to change ‘ in factors other than price of the commodity, it is called changes in supply.
  • It is the result of change in technology, govt, policies, prices of related goods etc.
  • Change in supply means- increase in supply & decrease in supply.
  • Price remaining the same when supply rises due to change in factors other than price, it is called increase in supply.
  • Likewise, price remaining the same when supply falls due to change in factors other than price, it is called decrease in supply.

In this case the supply curve shifts from its original position to rightward when supply increases and to leftward when supply decreases. Thus, change in supply curve as a result of increase and decrease in supply, is technically called shift in supply curve.

ca-foundation-business-economics-study-material-supply-4
In the figure above-

  • Original supply curve is SS. At OP price, OQ quantity is being supplied.
  • As the supply changes, the supply curve shifts either to the right (S1S1)or to the left (S2S2)
  • At S1S1, OQ1, quantity is being supplied at the price OP. This shows increase in supply. More quantity is being supplied at same price. It is denoted by rightward shift in supply curve.
  • At S2S2, OQ2 quantity is being supplied at the price OP. This shows decrease in supply. Less quantity is being supplied at same price. It is denoted by leftward shift in supply curve.

Elasticity of supply

  • Price elasticity of supply measures the degree of responsiveness of quantity supplied of a commodity to a change in its own price.
  • In other words, the elasticity of supply shows the degree of change in the quantity supplied in response to change in the price of the commodity.
  • Elasticity of supply can be defined “as a ratio of the percentage change in the quantity supplied of a commodity to the percentage change in its own price”.
  • It may be expressed as follows –
    ca-foundation-business-economics-study-material-supply-5
  • Since the law of supply establishes positive relationship between price and quantity supplied, the elasticity of supply would be positive.
  • However, in case of decreasing cost industry elasticity of supply is negative.
  • The value of elasticity co-efficient will vary from zero to infinity.

The elasticity of supply, according to its degree, may be of following types:-

1. Perfectly Inelastic Supply: Es = 0:
When a change in the price of a commodity has no effect on its quantity supplied, then supply is perfectly inelastic.
E.g. – If price rises by 20% and the quantity supplied remains unchanged then Es = 0/20 = 0. In this case, the supply curve is a vertical straight line curve parallel to Y-axis as shown in the figure.
ca-foundation-business-economics-study-material-supply-6
The figure shows that, whatever the price quantity supplied of the commodity remains unchanged at OQ.

2. Perfectly Elastic Supply: (Es = ∞):
When with no change in price or with very little change in price, the supply of a commodity expands or contracts to any extent, the supply is said to be perfectly elastic. In this case, the supply is a horizontal straight line and parallel to X-axis.
ca-foundation-business-economics-study-material-supply-7
The figure shows (Es = ∞) that, at given price supply is ever increasing.

3. Unit Elastic Supply : (Es =1):
When the percentage change in price is equal to percentage change in quantity supplied, then the supply is said to be unit elastic.
E.g. – If price rises by 10% and the supply also rises by 10% then, E= 10/10=1
ca-foundation-business-economics-study-material-supply-8
In this case the straight line supply curve SS when extended will pass through origin.

4. Relatively/More Elastic Supply: (E>1):
When a small change in price leads to big change in quantity supplied, then the supply is said to be relatively or more elastic. E.g. – If price rises by 10% and supply rises by 30% then,
E= 30/10 = 3>1. The coefficient of elasticity would be somewhere between ONE and INFINITY. The elastic supply curve is flatter as shown below-
ca-foundation-business-economics-study-material-supply-9
Supply curve SS is flat suggesting that the supply is more elastic. In this case the supply curve SS when extended will pass through Y-axis.

5. Relatively Inelastic Or Less Elastic Supply: (Es<1).
When a big change in price leads to small change in quantity supplied, then supply is said to relatively inelastic or less elastic.
E.g. – If price rises by 30% and supply rises by 10% then, Es = 10/30 = 1/3 < 1. The coefficient of elasticity would be somewhere between ZERO and ONE. The supply curve in this case has steep slope as shown below –
ca-foundation-business-economics-study-material-supply-10
Supply curve SS is steeply sloped suggesting that supply is less elastic. In this case the supply curve SS when extended will pass through X-axis.

Measurement of Elasticity of Supply

The different methods of measuring price elasticity of supply are:

  1. The Percentage or Ratio or Proportional Method,
  2. The Point or Geometric Method, and
  3. The Arc Method

1. The Percentage Method:
Thus method is based on the definition of elasticity of supply. The coefficient of price elasticity of supply is measured by taking ratio of percentage change in supply to the percentage change in price. Thus, we measure the elasticity by using the following formula-
ca-foundation-business-economics-study-material-supply-11

  • If the coefficient of above ratio is equal to ONE, the supply will be unitary.
  • If the coefficient of above ratio is MORE THAN ONE, the supply is relatively elastic.
  • If the coefficient of above ratio is LESS THAN ONE, the supply is relatively inelastic.

2. The Point Or Geometric Method:
In point elasticity method, we measure elasticity at a given point on a supply curve.
We can measure E at point ‘R’ in the following manner

  • Extend the supply curve ‘S’ towards the extension of X-axis so that it cuts X-axis at T.
  • Draw a perpendicular from ‘R’ cutting X-axis at ‘M’
  • Take the ratio of intercepts MT and OM.
    Es = MT/OM

ca-foundation-business-economics-study-material-supply-12
In the figure MT > OM, elasticity is GREATER THAN ONE.

ca-foundation-business-economics-study-material-supply-13
In the adjoining figure, supply curve when extended meets X-axis to the right of the point of origin so that
Es = MT/OM < 1
i.e. MT<OM and so elasticity is LESS THAN UNITY

ca-foundation-business-economics-study-material-supply-14
In the adjoining figure, supply curve when extended meets X-axis exactly at the point of origin so that
Es = MT/OM = 1,
i.e. MT = OM and so elasticity of supply is EQUAL TO UNITY/ONE.

3. The Arc Elasticity Method:
Under this method we measure elasticity of supply over an ARC of the supply curve. The arc elasticity is a measured of the “average elasticity” i.e. elasticity at MID-POINT that connects the two points on the supply curve. Thus, an arc is a portion of a curved line, hence a portion of supply curve. The formula used is
ca-foundation-business-economics-study-material-supply-15

Equilibrium Price

  • Equilibrium means a market situation where the quantity demanded is equal to quantity supplied. Thus, the two factors determining equilibrium price are market demand and market supply.
  • Equilibrium price is the price at which the sellers of a good are willing to sell the quantity which buyers want to buy. Thus, equilibrium price (also called market clearing price) is the price at which demand and supply are equal.
  • At equilibrium price both sellers and buyers are satisfied.
  • At equilibrium price, there is neither SHORTAGE nor SURPLUS. So at equilibrium price, market is said to be CLEARED.

The following table and figure explains the equilibrium price.
ca-foundation-business-economics-study-material-supply-16
ca-foundation-business-economics-study-material-supply-17

  • Equilibrium is struck a point E where the demand and supply curve intersect each other.
  • At E, equilibrium price is OP i.e. Rs. 3 and equilibrium quantity is OQ ie. 300 units.
  • When the price is Rs. 5 per unit, the quantity demanded is 100 units and quantity supplies is 500 units. It is situation where market demand < market supply and there is excess supply i.e., surplus supply. At a given price, sellers are willing to sell more than what buyers are ready to buy. As a result of pressure of excess supply the market price falls to Rs. 4.
  • At a price of Rs. 4, the pressure of excess supply still continues and hence the price falls further to Rs. 3.
  • At a price of Rs. 3, the market is CLEARED as the quantity demanded and supplied are equal to each other. There, is no SURPLUS.
  • Thus, we can conclude that pressure of excess supply (surplus) reduces the price.
  • Similarly, if the price is Rs. 1, the quantity demanded is 500 units and quantity supplied is 100 units. It is a situation where market demand > market supply and there is excess demand or SHORTAGE of supply. As a result of excess demand or SHORTAGE of supply the market price will rise. So long as pressure of excess demand continues price will rise i.e. till point E. At point E, excess demand is eliminated and quantity demand and supplied are equal to each other. The market has CLEARED.
  • Thus, we can conclude that pressure of excess demand (shortage of supply) increases the price.
  • The equilibrium price is determined by the intersection between demand and supply therefore, it is also called as the MARKET EQUILIBRIUM.