An open box with a square base is required to have a volume of 10 cubic feet. Assume the box is to be made from a square piece of cardboard that is has original dimensions (x + 2h)-by-(x + 2h) by cutting out 4 h-by-h squares on the corners of the cardboard and folding up the sides where h is the height of the open box sides (see figure below)

Base length x h by h square cut out to form open box

A] Express the surface area A(x) of the box as a function of the length of the base x.

B] Use a graphing utility to graph A(x) and determine the dimensions of an open box with the smallest surface area possible.