Question

Find the perimeter of the adjoining figure, which is a semicircle including its $10cm$ diameter.

Answer 1

Given diameter $=d=10cm$

$\Rightarrow$ Radius $=r=\frac{d}{2}$
$=\frac{10}{2}=5cm$

Perimeter of figure $=$ (perimeter of semi circle) + (length of Diameter)

$=\frac{2\pi r}{2}+2r$

Perimeter $=\pi r+2r$
$=r(\pi +2)$
$=\left(5\right(\pi +2\left)\right)cm$

Therefore, perimeter $=(5\pi +10)cm$