MENU

RD Chapter 15 Areas Related to Circles Ex 15.2 Solutions

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.

Answer - 1 : - Radius of the circle (r) = 4 cm
Angle at the centre subtended an arc = 30°

Question - 2 : - Find the angle subtended at the centre of a circle of radius 5 cm by an arc of length (5π/3 cm.

Answer - 2 : -

Radius of the circle (r) = 5 cm 571
Length of arc = 5π/3 cm
Let θ be the angle subtended by the arc, then

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.

Answer - 3 : -

Length of an arc = 20π cm
Angle subtended by the arc = 144°
Let r be the radius of the circle, then

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.

Answer - 4 : -

Length of arc = 15 cm
Angle subtended at the centre = 45°
Let r be the radius of the circle, then

Question - 5 : - Find the angle subtended at the centre of a circle of radius ‘a’  by an arc of length (aπ/4)  cm.

Answer - 5 : -

Radius of the circle (r) = a cm
Length of arc = aπ/4   cm
Let θ be the angle subtended by the arc at the centre, then

Question - 6 : - A sector of a circle of radius 4 cm contains an angle of 30°. Find the area of the sector.

Answer - 6 : -

Radius of the sector of a circle (r) = 4 cm
Angle at the centre (θ) = 30°

Question - 7 : - A sector of a circle of radius 8 cm contains an angle of 135°. Find the area of the sector.

Answer - 7 : -

Radius of the sector of the circle (r) = 8 cm
Angle at the centre (θ) = 135°

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.

Answer - 8 : -

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

Question - 9 : - The area of a sector of a circle of radius 5 cm is 5π cm2. Find the angle contained by the sector.

Answer - 9 : -

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

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]

Answer - 10 : -

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

Free - Previous Years Question Papers
Any questions? Ask us!
NodeJS Interview Questions Answers
ASP.Net Interview Questions Answers
Interview Questions Answers
×