Question

A right triangle ABC with sides $5$cm, $12$cm and $13$cm is revolved about the side $12$cm. Find the volume of the solid so obtained.

Answer 1

When the Triangle is rotated the so obtained solid is cone

With height $12cm$ and radius $5cm$

Volume of cone is $\frac{1}{3}\pi r^{2}h$

$=\frac{1}{3}\times \frac{22}{7}\times 5\times 5\times 12$

$=\frac{75\times 22}{7}=235.71c{m}^3$