First, you have to set up the equation. In this case, we would plug in what we know into the volume of a cylinder equation (V=


h).
We get:
980

=

(

)(h)
Then, after solving for what we know:
980

= 49

(h)
Divide both sides by 49

. The

cancels out and you're left with:
20= h
So the height of the cylinder is 20.