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

We have, 

Based radius of conical cap = r = 7cm 

Vertical height = h = 24 cm 

∴slant height = l = \(\sqrt{r^2+h^2}\)

= \(\sqrt{49+576}\)

= 25 cm 

Required area of sheet,

= 10 × πrl = 10× \(\frac{22}{7}\) ×7×25 cm² 

= 5500 cm²