Comparing Volumes of Cylinders: Is a Larger Radius or Height More Important?

[bobsmith76]

which is greater or are they equal: one cylinder with 2 radius and height 10, or one with 1 radius and height 20

I thought they would be equal because the first one is

4pi * 10 = 40pi

and the second is

2pi * 20 = 40pi

But my book says the first is greater. don't understand why

 

[pwsnafu]

Start again. What's the formula for volume of a cylinder?

 

[bobsmith76]

ok, pir^2h not pi(2r)h

now i get it