Question

A sector of a circle with radius $18\text{cm}$ has central angle ${120}^{\circ }$. Find the area of the sector. Use $\pi =3.14$

Answer 1

Given, radius, $r=18\text{cm}$, central angle, $\theta ={120}^{\circ }$, $\pi =3.14$

$\begin{array}{cc}\text{Area of sector}& =\frac{\theta }{{360}^{\circ }}\times \pi r^2\\ & =\frac{{120}^{\circ }}{{360}^{\circ }}\times 3.14\times 18\times 18\\ & =\frac{1}{3}\times 3.14\times 324\\ & =3.14\times 108\\ & =339.12\end{array}$

Hence, area of the sector is $339.12{\text{cm}}^2$.