You have a picture.....use that as your sketch
2.volume = l x w x w = lw^2 (w= side of the square)
3. 54000 cu in is max
4. l + 4w =180 or l= 180-4w substitute this in to #2
(180-4w)(w^2) = volume
(180w^2 - 4w^3) a 'local' max will be where slope = 0
Derivative 360 w - 12w^2 = 0
w = 0 or 30 (throw out '0' obviously)
w=30 then l = 180-4w=60
volume max = l x w x w = 60 x 30 x 30 = 54000 cu in