Find the lateral area and surface area of cone

Question

asked Jul 7, 2020 45.2k views

1 Answer

Cetver · Answer 1 · 2020-07-11T21:58:27+0000

Answer:

$\large\boxed{L.A.=168\pi\ in^2}\\\boxed{S.A.=232\pi\ in^2}$

Explanation:

The formula of a lateral area of a cone:

$L.A.=\pi rl$

r - radius

l - slant height

The formula of a surface area of a cone:

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

We have r= 8in and l = 21in. Substitute:

$L.A.=\pi(8)(21)=168\pi\ in^2$

$S.A.=\pi(8^2)+168\pi=232\pi\ in^2$