The formulas used to find the perimeter of a rectangle or square are only used for two-dimensional objects, so they cannot be used to find the perimeter of a three-dimensional box. The term perimeter refers to the distance around a polygon, which is a two-dimensional shape with at least three sides.
The formula for calculating the perimeter of a rectangle is 2L + 2W, where L is the length of the rectangle and W is the width of the rectangle. If a rectangle has a length of 2 feet and a width of 4 feet, its perimeter equals 12 feet, or 2(4) + 2(2).
The formula for calculating the perimeter of a square is 4a, where a is the length of one of the sides of the square. If each side of the square has a length of 3 feet, the perimeter of the square is 12 feet, or 4(3).