Question

The area of the shaded portion in the figure is

• A. $7.5\pi sq.units$
• B. $6.5\pi sq.units$
• C. $5.5\pi sq.units$
• D. $4.5\pi sq.units$

Answer 1

The correct option is D $4.5\pi sq.units$

Given that radius of outer semicircle and inercircle is 5 cm and 4 cm

Then area of outer semicircle=$\frac{\pi r^2}{2}=\frac{\pi (5{)}^2}{2}=12.5\pi$ sq cm

and area of inner semi circle =$\frac{\pi r^2}{2}=\frac{\pi (4{)}^2}{2}=8\pi$ sq cm

Then area of shaded portion in figure=$12.5\pi -8\pi =4.5\pi$ sq cm