Question

What is the surface area of the right cone below?

A. 52 units2
O B. 1047 units2
C. 6870 units2
D. 5471 units2

Answer 1

First find height using Pythagorean theorem.

`h^2+4^2=13^2\implies h=√(153)\approx12.37`.

Then use cone surface area formula and compute the result:

`A=\pi r(r+√(h^2+r^2))\approx\boxed{68\pi}\mathrm{units^2}`.

Hope this helps.