Question

A sector of a circle with radius $20$ $cm$ has central angle ${90}^o$. Find the area of the sector. $(\pi =3.14)$.

Answer 1

Given, radius, $r=20$ $cm$, central angle, $\theta ={90}^o$, $\pi =3.14$
Area of sector $=\frac{\theta }{{360}^o}\times \pi r^2$
$=\frac{{90}^o}{{360}^o}\times 3.14\times 20\times 20$
$=\frac{1}{4}\times \frac{314}{100}\times 20\times 20$
$=314$
$\therefore$ the area of sector is $314{cm}^2$.