Question

The given figure shows a rectangle ABCD inscribed in a circle as shown alongside.
If AB=28 cm and BC=21 cm, then find the area of the shaded portion of the given figure.

Answer 1

Area of shaded portion=area of circle-area of ABCD

$=\pi \times {\left(\frac{AC}{2}\right)}^2-AB\times BC$

Using Pythagoras theorem; $AC=\sqrt{{AB}^2+{BC}^2}=\sqrt{{28}^2+{21}^2}=35㎝$

$\therefore$ Area of shaded portion$=(\frac{22}{7}\times \frac{35}{2}\times \frac{35}{2})-(28\times 21)$

$=962.5-588$

$=374.5c{m}^2$