Question

Question 7
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. $[Assume\pi =\frac{22}{7}]$

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 $=\sqrt{r^2+h^2}$
$=\left[\sqrt{(7{)}^2+(24{)}^2}\right]cm=\left(\sqrt{625}\right)cm=25cm$

CSA of 1 conical cap $=\pi rl$
$=(\frac{22}{7}\times 7\times 25)c{m}^2=550c{m}^2$

CSA of 10 such conical caps $=(10\times 550)c{m}^2=5500c{m}^2$

Therefore, $5500c{m}^2$ sheet will be required.