How much foil is required to cover a rectangular box that is 4in. by 8in. by 5in.? use 3.14 as an aproximation for pi. where appropriate.

1 answer

The foil is to cover the entire
surface area. Therefore, we need to calculate the surface area of the
box. There are six sides or 3 pairs.
1. The front and back areas are equal.
2. The right and left areas are equal.
3. The top and bottom areas are equal.
Therefore, we calculate 3 areas and
multiply each by 2 to get 6 areas.

As = 2(4 * 5) + 2(8 * 5) + 2(8 * 4)
= 40 + 80 + 64 = 184 sq. in. of
foil required.
40 = Area of front and rear.
80 = right and left.
64 = area of top and bottom