Question

Find the area of the shaded region

Answer 1

$\begin{array}{c}2d=42\\ d=21cm\end{array}$

Radius of semi circle $=\frac{21}{2}=10.5cm$

Area of 4 semi circles$=4\frac{\pi r^2}{2}$

Area of shaded part $=4\times \frac{22}{7}\times \frac{1}{2}\times 10.5\times 10.5$

Area of shaded par$=44\times 1.5\times 10.5=693c{m}^2$