Question

AB is a chord of a circle of centre O and radius $4cm$. AB is of length $4cm$. Find the area of the sector of the circle formed by chord AB.

Answer 1

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

Here, $\theta =60°$, because in $△OAB$, $OA=AB=BD=4cm$, therefore $△OAB$ is an equilateral triangle

$\therefore$Area of sector$=\frac{60°}{360°}\times \pi \times 4\times 4=\frac{8\pi }{3}c{m}^2$