Question

Find the surface area of a cylinder with a base diameter of 6 in and a height of 9 in. Write your answer in terms of II, and be sure to include the correct unit.

Answer 1

The surface area of a cylinder (S) with radius "r" and height "h" is:

$S=2*\pi *r^2+2*\pi *r*h$

Also, radius = diameter/2

Given:

r = 6/2 = 3 in

h = 9 in

Substitute the values in the equation and find S:

$\begin{gathered} S=2\pi *3^2+2\pi *3*9 \\ S=2\pi *9+2\pi *27 \\ S=18\pi+54\pi \\ S=72\pi\text{ in}^2 \end{gathered}$

Answer: The surface area is 72π in².