Question

Find the area of the shaded part in the figure. (Use $\pi =3.14$)

Answer 1

$AC$ is the diameter of the circle.
In the right angled triangle $ADC$, we have
$A{C}^2=A{D}^2+D{C}^2$ (Pythagoras theorem)
$A{C}^2=5^2+{12}^2$
$A{C}^2=25+144$
$A{C}^2=169$
$AC=13$ cm
Radius of the circle $=$ $\frac{AC}{2}=\frac{13}{2}=6.5$ cm

Area of the shaded part $=$ Area of the circle $-$ Area of the rectangle
$=$ $\pi r^2-lb$
$=$ $3.14\times {6.5}^2-(5\times 12)$
$=132.665-60$
$=72.665$ $c{m}^2$