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 right-angled $∆ABC$ is revolved about its side 12 cm, a cone with height (h) as 12 cm, radius (r) as 5 cm, and slant height ($l$) 13 cm will be formed.

Volume of cone= $\frac{1}{3}\pi$r²h
= $\frac{1}{3}$ × $\pi$ × 5 cm × 5 cm × 12 cm
= 100$\pi$ cm³
Volume of the cone is 100$\pi$ cm³