A right cone has a radius of 13 cm and an altitude of 52 cm. Find its surface area. A. 2,668.7 cm2 B. 865.8 cm2 C. 849.5 cm2 D. 2,720.0 cm2

Question

asked Nov 12, 2020 220k views

1 Answer

Amittn · Answer 1 · 2020-11-16T13:11:27+0000

Answer:

Option B.
$865.8\pi\ cm^(2)$

Explanation:

we know that

The surface area of the cone is equal to

$SA=\pi r^(2) +\pi rl$

we have

$r=13\ cm$

$h=52\ cm$

Find the slant height l

Applying Pythagoras \theorem

l^(2)=r^(2) +h^(2)

substitute the values

l^(2)=13^(2) +52^(2)

l^(2)=2,873

$l=53.6\ cm$

Find the surface area

$SA=\pi(13)^(2) +\pi(13)(53.6)=865.8\pi\ cm^(2)$