Question

Find circumference(in cm) of a circle of diameter $140cm$.

Answer 1

Diameter of circle $\left(d\right)=140cm$

$\Rightarrow$ Radius of circle $\left(r\right)=\frac{d}{2}=\frac{140}{2}=70cm$

$\therefore$ Circumference of circle $=2\pi r=2\times \frac{22}{7}\times 70=440cm$