Question

Find the area of the shaded portion in the figure.

Answer 1

Area of the trapezium $=\frac{1}{2}\times h(a+b)$
$=\frac{1}{2}\times 100(120+160)$
$=50\times 280$
$=14000$ cm${}^2$

Area of the rectangle $=l\times b$
$=40\times 20$
$=800$ cm${}^2$

Area of the circle $=\pi r^2$
$=\frac{1}{2}\times 7\times 7$
$=22\times 7$
$=154$ cm${}^2$

Area of the shaded portion = Area of the trapezium - Area of the rectangles - Area of the circle
$=14000-800-154$
$=13046$ cm${}^2$