SOLUTION: The total surface area of a right cylinder is 84πcm² and the altitude is 11 cm. Find the radius of the base.

Algebra ->  Surface-area -> SOLUTION: The total surface area of a right cylinder is 84πcm² and the altitude is 11 cm. Find the radius of the base.       Log On


   



Question 1038596: The total surface area of a right cylinder is 84πcm² and the altitude is 11 cm. Find the radius of the base.
Answer by addingup(3677) About Me  (Show Source):
You can put this solution on YOUR website!
84π = 263.89
263.89/11 = 24 this is the surface area of the base. The base is a circle
What is the area for a circle?
πr^2 = A and we want to find r:
r^2 = A/π
r^2 = 24/π
r^2 = 7.64 Take the square root on both sides
r = 2.764 this is the radius of the base out to 3 decimals. If you only need 2 decimals, then 2.76
John