Question 1040831
If x = width, l = length, then h = 2x.

==> {{{x^2*l = 9}}}, and {{{A[s] = 6lx+4x^2}}}, where {{{A[s]}}} is the total surface area.

There is be an absolute minimum at {{{x = 3/root(3,4) = highlight((3/2)*root(3,2))}}} feet.

==> {{{highlight(l = 2root(3,2))}}} feet, and height = {{{highlight(3root(3,2))}}} feet.