Question

Help please!

Answer 1

y=2pi r cubed, probably.

Answer 2

Well first thing, what's the volume of a cylinder? What's the general formula?

Answer 3

\[V=\pi r^2 h\] is the volume of a cylinder so your problem states your height is 2r, so we substitute 2r for the height.

\[V=\pi r^2(2r) \implies 2\pi r^2 \times r \implies 2 \pi r ^{2+1} \implies 2\pi r ^3\]