Find the area of the shaded region

Question

This is the Figure, $ABCD$ is a square , $AB = BC = CD = DE = 21cm$. $AC$ and $BD$ are the diagonals

of the square. The two semi circles are drawn with $AD$ and $BC$ as diameter. Find total are of

the black and red coloured regions.(Take $\pi = 22/7$).

Answer 1

Area of black region is half of area of square, i.e. $\frac12\times 21^2$.

Area of red region is area of a circle with radius $21/2$, i.e. $\frac{22}7\left(\frac{21}2\right)^2$

Add them.