Question

Find the area of shaded portion.


[3 marks]

Answer 1

Area of shaded region=Area of the circle-Area of four triangles-Area of a square
Area of four triangles =$4\times \frac{1}{2}\times 7\times 7=\frac{4\times 49}{2}=2\times 49=98c{m}^2$
Area of square=$(side{)}^2=(7{)}^2=49c{m}^2$
[1.5 marks]

Area of the circle
$=\pi r^2=\frac{22}{7}\times \frac{21}{2}\times \frac{21}{2}=\frac{11\times 3\times 21}{2}=\frac{693}{2}=346.5c{m}^2$
Area of shaded region=(346.5-98-49)
=$199.5c{m}^2$
[1.5 marks]