Parameterize this surface (call it
) by

with
and
. Take the normal vector to
to be

Then the area of
is



The answer would be 7(a - 1)
A rotation is a rigid motion
Answer: 9 inches
Explaination: The volume of a cylinder, V = (πr^2)H, so H = V/(πr^2).
Using the parameters you specified, H = 324π/[(π)(6^2)] = 324π/36π = 324/36 = 9 inches