can't find an equation to use for this max/min problem?

Question

can't find an equation to use for this max/min problem

an open box is to be made from a sheet of card board with area 24 ft. squared by cutting out even squares (sides x ft.)from the corners and folding up. what are the dimensions of the box for the maximum volume?

Answer 1

I stick by my prior answer of 4' x 16' x 16' starting with a piece of cardboard that is 24' feet squared (24' x 24').