A box with a square base of side a is three times higher than its width. Express the volume V of the box as a function of a.

V (a) = ?

Volume of a box is length x width x height.

Here its bottom is square, with side = a (its side has length a) The box is three times higher. This means 3 times a is its height. So putting it together:length = a, width = a (square base) height = 3a (three times higher than it is wide) V=a⋅a⋅3a=3a3