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Find the area of a sector of circle of radius 21 cm and central angle 120°

Solution:

Given, central angle, θ = 120°

Radius of circle, r = 21 cm

We have to find the area of a sector of the circle.

Area of sector = πr²θ/360°

= π(21)²(120°)/360°

= π(21)²(1/3)

= (22/7)(21)(21)(1/3)

= (22/7)(21)(7)

= (22)(21)

= 462 square cm.

Therefore, the area of the sector is 462 square cm.

✦ Try This: Find the area of a sector of circle of radius 12 cm and central angle 90°.

Given, central angle, θ = 90°

Radius of circle, r = 12 cm

We have to find the area of a sector of the circle.

Area of sector = πr²θ/360°

= π(12)²(90°/360°)

= (22/7)(12)(12)(1/4)

= (11/7)(6)(12)

= 113.14 square cm

Therefore, the area of the sector is 113.14 square cm.

☛ Also Check: NCERT Solutions for Class 10 Maths Chapter 12

NCERT Exemplar Class 10 Maths Exercise 11.3 Sample Problem 2

Find the area of a sector of circle of radius 21 cm and central angle 120°

Summary:

A sector of a circle is a pie-shaped part of a circle made of the arc along with its two radii. The area of a sector of circle of radius 21 cm and central angle 120° is 462 square cm

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