Find the lateral and surface area of each cone

Question

asked Sep 22, 2020 36.1k views

1 Answer

Jens Schwarzer · Answer 1 · 2020-09-26T01:23:50+0000

Answer:

$\large\boxed{L.A.=153\pi\ mm^2}\\\boxed{S.A.234\pi\ mm^2}$

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= 9mm and l = 17mm. Substitute:

$L.A.=\pi(9)(17)=153\pi\ mm^2$

$S.A.=\pi(9^2)+153\pi=81\pi+153\pi=234\pi\ mm^2$