13 The volume of the square-based box shown at right is 256 cm3. a Find h in terms of I. If the box has an open top, find: b the surface area, A, in terms of / only h c the dimensions of the box if the surface area is to be a minimum d the minimum area. (Hint: = = 1-1.) 14 A closed, square-based box of volume 1000 cm is to be constructed using the minimum amount of sheet metal possible. Find its dimensions