Math  Please Help
posted by Barb .
The surface area of a right circular cylinder is 1200 cm^2 . If the height of the cylinder is twice its diameter, find the dimensionsof the cylinder.
I know th formula for SA is SA = 2pir^2 + 2pirh
I know h = 2d.
I know r = 1/2 d
What is h in relations to r? Is is 4r?

you are correct. h = 4r
1200 = pi r^2 h = pi * r^2 * 4r = 4pi r^3
... 
I don't no