Answer
The length of a side of the triangle is 12 cm.
Work Step by Step
Let X represent the length of a side of the square.
The length of a side of the triangle is 4 centimeters more than the length of a side of the square, which equals X + 4.
The perimeter of a triangle is equal to the sum of all its sides.
The perimeter of the triangle equal x + 4 + x + 4 + x + 4 = 3x + 12
The perimeter of a square equals 4 $\times$ the length of its side.
The perimeter of a square equals 4 $\times$ X = 4X
Since the perimeter of the triangle (3X + 12) is 4 centimeters more than the perimeter of the square (4X), we set up the following equation.
3X + 12 = 4X + 4
8 = X
The length of a side of the triangle is X + 4. Since X = 8, the length of a side of the triangle is 8 + 4 = 12.