An open box with a square base (see figure) is to be constructed from 160 square inches of material. The height of the box is 3 inches. What are the dimensions of the box? (Hint: The surface area is S = x2 + 4xh.)

Question

1 . in. (length) × 2 . in. (width) × 3 . in. (height)

Answer 1

S=x²+4xh= x²+12x =160.
x²+12x -160=0

x=- 6±sqrt(36+160) .
x1=-20 (impossible),
x2= +8
1. 8 in;
2. 8 in;
3. 3 in.