Question

A cylinder has a circumference of
`12 \pi` cm and a height that is half the radius. What is the total surface area of the cylinder?

Answer 1

Circumference: 12 π
2 r π = 12 π
r = 12 π : 2 π
r = 6 cm, h = 6 : 2 = 3 cm
The total surface area of the cylinder:
S A = 2 · r² π + 2 r h π =
= 2 · 6² π + 2 · 6 · 3 π = 72 π + 36 π = 108 π cm²
Answer: The total surface is 108 π cm².