A joker’s cap is in the form of a right circular cone of base radius 7 cm and height 24 cm. Find the area of the sheet required to make 10 such caps.
Radius of the cone (r) = 7 cm
Height of the cone (h) = 24 cm
Let l be the slant height
∴ l = √h2 + r2
⇒ l = √242 + 72
⇒ l = √625
⇒ l = 25 m
Sheet required for one cap = Curved surface of the cone
= πrl cm2
= (22/7 × 7 × 25) cm2
= 550 cm2
Sheet required for 10 caps = 550 × 10 cm2 = 5500 cm2
