An open box with a square base is to be constructed from 84 square inches of material. what should be the dimensions of the base if the height of the box is to be 2 inches? (Surface area: S=x^2+4xh) Substitute 2 for h, and 84 for S and solve for x. You will get x=6 and x=-14. Ignore the negative answer. The dimensions of the base are 6 inches by 6 inches. Each of the 4 sides are 6x2 or 12 square inches each. That's 48 square inches. The base is 6x6 or 36 square inches. So that's 48 + 36 = 84 square inches. Edwin