Question

Find the area of the sector of a circle with radius $4cm$ and of angle ${30}^{\circ },$ Also, find the area of the corresponding major sector (Use $\pi =3.14).$

Answer 1

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

$\frac{\theta }{{360}^o}\times 3.14\times 4\times 4c{m}^2$

$=\frac{12.56}{3}c{m}^2=4.19c{m}^2$ (approx)

Area of the corresponding major sector $=\pi r^2-$ Area of sector $OAPB$

$=(3.14\times 4\times 4-4.19)c{m}^2=(50.24-4.19)c{m}^2$

$=46.05c{m}^2=46.4c{m}^2$ (approx.)