Question:
Note Use $\pi=\frac{22}{7}$, unless stated otherwise.
Find the curved surface area of a cone with base radius 5.25 cm and slant height 10 cm.
Solution:
Radius of the base, r = 5.25 cm
Slant height, l = 10 cm
$\therefore$ Curved surface area of the cone $=\pi r l=\frac{22}{7} \times 5.25 \times 10=165 \mathrm{~cm}^{2}$
Thus, the curved surface area of the cone is 165 cm2.