Calculate the perimeter of a square, given its side length, and find the side length if the perimeter is known.

Given the formula for the perimeter of a square, P = 4 * a, where a is the side length: 1. If the perimeter is P = 44 cm, then the side length is a = P / 4 = 44 / 4 = 11 cm. 2. If the side length is a = 25 cm, then the perimeter is P = 4 * 25 = 100 cm.