Question

The total surface area of right circular cone is 360∏ m², the height of the right circular cone (in m) ; r=10m

• A. 15m
• B. 18m
• C. 24m
• D. 20m

Answer 1

Answer:

C. 24m

Let 'l' be the slant height of the right circular cone.

According to the question

$A=\pi rl+\pi r^2$

$360\pi=[(\pi \times 10 \times l)+(\pi \times 10^2)]$

$360=10l+100$

$36=l+10$

$l=26m$

now,

$l^2=r^2+h^2$

$26^2=10^2+h^2$

$h^2=676-100$

$h=24$