Question

In the given figure, $OACB$ is a quadrant of a circle. The radius $OA=3.5cm,OD=2cm$. Calculate the area of the shaded portion.

• A. $6.225c{m}^2$
• B. $6.25c{m}^2$
• C. $6.116c{m}^2$
• D. $4.25c{m}^2$

Answer 1

The correct option is C $6.116c{m}^2$

Area of quadrant $=\frac{1}{4}\times \pi r^2$
$=\frac{1}{4}\times 3.14\times {3.5}^2$
$=9.616c{m}^2$.
Area of $ADO=\frac{1}{2}\times AO\times OD$
$=\frac{1}{2}\times 3.5\times 2$
$=3.5c{m}^2$.
Hence, area of shaded portion$=9.616-3.5=6.116c{m}^2$.