Question

Diameter of the base of a cone is 10.5 cm and its slant height is 10 cm. Find its curved surface area.

Answer 1

Diameter, d = 10.5cm

Radius, r = $\frac{10.5}{2}$ cm = 5.25 cm
Slant height, l = 10 cm
Curved surface area = $\pi rl$
$= \frac{22}{7} × 5.25 × 10$
= 165 cm²

Thus, curved surface area of the cone = 165 cm².