A cone has a diameter of 8 units and a height of 8 units.

Its radius is ___ {2?,4?,8?,16?} units, and its volume is ___ {66.99?,133.97?,401.97?, 401.92?, 535.89?} cubic units. A cylinder with the same height and radius as the cone will have a volume of ___ {66.99?,133.97?,401.92?,535.89?}cub ic units. If a sphere has the same radius as the cylinder, its volume is {half?,two thirds?,four thirds?}the volume of the cylinder.