## Algebra: A Combined Approach (4th Edition)

Let $V$ be the volume of a cylinder. Let $h$ be the height of a cylinder. Let $r$ be the radius of a cylinder. $V=khr^2$ When height is halved and radius is doubled, $k\frac{h}{2}(2r)^2=2khr^2$ Since $khr^2=V$, $2khr^2=2V$ Volume is doubled.