Question

Calculate the area and perimeter of a quadrant of a circle of radius $21$ cm.

Answer 1

Given that $r=21cm$, $\theta ={90}^{\circ }$

Perimeter $=(\frac{\pi }{2}+2)r=(\frac{22}{7\times 2}+2)\times 21=75cm$

$Area=\frac{{90}^o}{{360}^o}\times \frac{\pi r^2}{4}=\frac{22}{7\times 4}\times 21\times 21=346.5c{m}^2$