Question

In a circle of radius 21 cm if an arc sustended at a arc 60 at centre find the length of the arc

Answer 1

$length \: of \: arc = \frac{ \alpha }{360} \ \: 2\pi {r} \\ length = \frac{60}{360} \times 2 \times \frac{22}{7} \times 21 \\ = \frac{1}{6} \times 2 \times 22 \times 3 \\ = \frac{1}{6} \times 6 \times 22 \\ = 22cm$