Question

A joker cap is in the form of a right circular cone of radius 7 cm. If l =25 cm, find the area of the sheet required for 12 such caps.

Answer 1

Given that a joker cap is in the form of a right circular cone.

Radius of the cone is, $r=7cm$

and slant height, $l=25cm$

to find out: Area of the sheet required for $12$ caps.

We know that, surface area of a cone $=2\pi rl$

$\therefore$ area of one cap $=2\times \frac{22}{7}\times 7\times 25=1100c{m}^2$

Hence, area of the sheet required for $12$ such caps $=12\times 1100=13200c{m}^2$.