A cylinder has a surface area of 250cm2. The height is twice as big as the radius. What is the height of the cylinder?

Answer 1

h = 2r

SA = 2πr^2 + 2πrh
= 2πr^2 + 2πr(2r)
= 6πr^2

6πr^2 = 250
r^2 = 125/(3π)
r = 3.6418..
h = 2r = 7.28....