Question

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

Answer 1

SOLUTION

given,

→ radius of circle, r = 21 cm

→ central angle, θ = 120°

We have to find the area of the sector formed by the two radii at 120°

So,

Area of sector = $\pi r^{2} \frac{ \theta }{360}$

$\\ \\ = = > \: \: \frac{22}{ \cancel{7}} \times 21 \times \cancel{21} \times \frac{ \cancel{120}}{ \cancel{360}} \\ \\ = = > \: \: 22 \times \cancel{3} \times 21 \times \frac{1}{ \cancel{3}} \\ \\ = = > \: \: 22 \times 21 \\ \\ = = > \: \: 462$

Hence, Area of the sector is 462 cm²