The curved surface of a right circular cone of height 15 cm and base diameter 16 cm is :

A. 60π cm²

B. 68π cm²

C. 120π cm²

D. 136π cm²

Answer: Option D

Solution(By Examveda Team)

h = 15 cm, r = 8 cm
So,
$$\eqalign{ & l = \sqrt {{r^2} + {h^2}} \cr & \,\,\,\,\,\, = \sqrt {{8^2} + {{\left( {15} \right)}^2}} \cr & \,\,\,\,\,\, = 17\,cm \cr} $$
∴ Curved surface area :
$$\eqalign{ & = \pi rl \cr & = \left( {\pi \times 8 \times 17} \right){\text{ c}}{{\text{m}}^2} \cr & = 136\pi {\text{ c}}{{\text{m}}^2} \cr} $$