Question

Will someone please solve this. I got 720pi but it was wrong

Answer 1

Formula for lateral surface area of cone is:
$A = \pi r l$
where l is length of diagonal or slant length of cone
$l = \sqrt{h^2 + r^2$

The given figure shows a symmetric double cone, so we need to only find lateral surface area of one come then double it to get surface area or entire figure.

$A = 2 \pi r \sqrt{h^2 + r^2}$

Now just sub in given values for radius and height:
r = 10, h  = 24

$A = 520 \pi$