Question

A joker’s cap is in the form of a right circular cone of base radius 7cm and height 24cm. Find the area of the sheet required to make 10 such caps.

Answer 1

It is given that

Radius of the cap = 7cm

Height of the cap = 24cm

We know that

Slant height of the cap

l = √(r² + h²)

By substituting the values

l = √(7² + 24²)

On further calculation

l = √(49 + 576) = √625

So we get

l = 25cm

We know that

Curved surface area of one cap = πrl

By substituting the values

Curved surface area of one cap = (22/7) × 7 × 25

So we get

Curved surface area of one cap = 550 cm²

So the curved surface area of 10 conical caps = 10 × 550 = 5500 cm²

Therefore, the area of the sheet required to make 10 such caps is 5500 cm².