Question

Find the radius of the circle whose area is $38.5m^2$.

Answer 1

$Area=\pi r^2$

$\Rightarrow 38.5=\frac{22}{7}\times r\times r$

$\Rightarrow 38.5\times 7=22\times r\times r$

$\Rightarrow 269.5=22\times r\times r$

$\Rightarrow \frac{269.5}{22}=r\times r$

$\Rightarrow 12.25=r\times r$

$Hence,r=3.5$