Question

The volume of a cone is $396$ mm${}^3$. If the height of the cone is $10.5$ mm, calculate the radius of its base. $(\pi =\frac{22}{7})$

Answer 1

Given: Volume of cone $V=396m{m}^3$

Height of cone $h=10.5mm$

We know, Volume of cone, $V=\frac{1}{3}\pi r^{2}h$

$\Rightarrow r^2=\frac{3V}{\pi h}$

$\Rightarrow r=\sqrt{\frac{3V}{\pi h}}$

$\Rightarrow r=\sqrt{\frac{3\times 396}{\frac{22}{7}\left(10.5\right)}}$

$\Rightarrow r\simeq 6$

Therefore, the radius of the cone is $6mm$