Question

The dimensions of a cuboid are 44 cm, 21 cm, 12 cm. It is melted and a cone of height 24 cm is made. Find the radius of its base. 

Given: For the cuboid, 

length (l) = 44 cm, breadth (b) = 21 cm, 

height (h) = 12 cm

For the cone, height (H) = 24 cm 

To find: Radius of base of the cone (r).

Answer 1

Volume of cuboid = l × b × h

= 44 × 21 × 12 cm³

Volume of cone = 1/3 πr²H

Since the cuboid is melted to form a cone, 

∴ volume of cuboid = volume of cone

...[Taking square root of both sides]

∴ The radius of the base of the cone is 21 cm.