Question

Hi there!

Can you help me with this question ? Thanks!

Answer 1

Hello Gary!

T.S.A of a cylinder = 2pir² + 2pirh
=2(9)² pi+ 2(9)(11)pi
= 162pi + 198pi
= 160pi in²

So as seen, the Correct Answer would be Option "D". 360 in²


Hope this Helps! Have A Wonderful Day! :)

Answer 2

Circumference = 2πr
Our cylinder's circumference: 2 * π * 9 = 18π

Surface area of cross section = πr² = π * 9² = 81π
* 2 since there is two cross sections: 81π * 2 = 162π

Surface area of rounded face, treat it like a rectangle: C*H
18π * 11 = 198π

Add the surface areas, 198π + 162π = 360π in²