__Maximize the area for two pens.__

Problem statement:

Two pens are to be constructed using a total of S feet of fencing.

One pen is to be a square H by H and the other is to be a rectangle

with one side twice as long as the other side; that is, X by 2X.

Determine the dimensions of the pens so that the enclosed areas are

as large as possible.

**The accompanying
animation uses S= 900 ft.**