Q:

Volume = r2h Surface Area = 2r2 + 2rh A cylinder has a radius of 2 feet and a height of 18 feet. Volume (to the nearest tenth) = cubic feet. Surface area (to the nearest tenth) = square feet.

Accepted Solution

A:
Answers:
volume of cylinder = 226.2 ft³
surface area of cylinder = 251.3 ft²

Explanation: 
Part I: getting the volume:
The correct rule to get the volume of the cylinder is as follows:
volume = πr²h
where:
π is a constant
r is the radius of the cylinder = 2 ft
h is the height of the cylinder = 18 ft
Substitute with the givens in the above equation to get the volume as follows:
volume = πr²h
volume = π * (2)² * 18
volume = 72π ft³ which is approximately 226.2 ft³

Part (2): getting the surface area:
The correct rule to get the surface area of the cylinder is as follows:
surface area = 2πr² + 2πrh
where:
π is a constant
r is the radius of the cylinder = 2 ft
h is the height of the cylinder = 8 ft
Substitute with the givens in the above equation to get the surface area as follows:
surface area = 2πr² + 2πrh
surface area = 2π(2)² + 2π(2)(18)
surface area = 8π + 72π
surface area = 80π which is approximately 251.3 ft²

Hope this helps :)