Question

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.

Answer 1

Radius(r) of the conical cap = 7 cm
Height (h) of the conical cap = 24 cm
Slant height (l) of the conical cap =$\sqrt{r^2+h^2}$
$=\sqrt{(7)^2+(24)^2}$ cm
$=(\sqrt{625})$ cm
=25 cm
CSA of 1 conical cap =$\pi rl$
$=(\frac{22}{7}×7×25)$ cm2
$=550$ cm2
CSA of 10 such conical caps = $(10×550)$ cm2=5500 cm2
Therefore, 5500 cm2 sheet will be required.