Question

Find circumference of a circle of diameter $4.2cm$.

• A. $13.2cm$
• B. $13.7cm$
• C. $14.2cm$
• D. $14.9cm$

Answer 1

The correct option is A $13.2cm$

Diameter of circle $\left(d\right)=4.2cm$

$\Rightarrow$ Radius of circle $\left(r\right)=\frac{d}{2}=\frac{4.2}{2}=2.1cm$

$\therefore$ Circumference of circle $=2\pi r=2\times \frac{22}{7}\times 2.1=13.2cm$

So, $\text{A}$ is the correct option.