Question

Find the circumference of the circle with the following radius: (Take $\pi =\frac{22}{7}$)
$21cm$

Answer 1

Let radius be =$r$

Circumference of a circle$=2\pi r$

$\Rightarrow$ $2\pi r=21cm$

$\Rightarrow$ $r=\frac{21}{2\pi }$cm

$\Rightarrow r=\frac{21\times 7}{2\times 22}$

$\Rightarrow$ $r=3.34cm$