Because a square has four equal sides you can use 4 x S
You can also treat a square like a rectangle and use the formula for a rectangle.
2 x length + 2 x width
S = side length of the square
Video # 1
Answers the following questions
How do you find the perimter of a rectangle that measures 5x8 units?
Video # 2
How do you find the perimeter of a rectangle using side length and diagonal length?
Example problem two involves finding the perimeter of a triangle in which you only have a measurement of one side and the diameter. You can use the property of a rectangle that states a rectangle has four right angles. As a result the diagonal creates a right triangle.