For this problem, we are given the relationship between the length and width of the rectangle. We need to determine the value of the width for a perimeter of 120 centimeters.
The problem states that the length is 3 times the width, therefore we have:
The perimeter of a rectangle is given by:
For a value of 120 centimeters, we have:
The width of the rectangle is equal to 15 centimeters.