Question

If right triangle ABC with sides 5 cm, 12 cm and 13 cm is revolved about the side 5 cm, then find the volume of the solid so formed.

Answer 1

When a right ∆ABC revolves about its side BC = 5 cm the solid thus obtained is single cone having radius = r = 12 cm and height = h = 5 cm. 

V = volume of cone = (1/3)πr² h units³ 

V = (1/3) x π x (12)² x 5 = 240 π cm³ 

Hence, the required volume of the solid cone is 240 π cm³