Since each one is a square, each side has to be the same length. I know that 12×12 is 144, so for the first square, each side is 12 inches. Then, use the formula to determine the perimeter. 4×12=48, so the first perimeter is 48 inches. For the second, I know that 9×9=81, so each side is 9. 4×9=36, so the perimeter is 36. For the last, each side is 18 inches. 4×18=72, so the perimeter is 72 inches.