The perimeter of the rectangle is 18 cm, its length is 6 cm. What is the width of this rectangle.

To solve this problem, remember that the perimeter of a rectangle is the sum of the lengths of all its sides. Since in a rectangle the opposite sides are equal, then P = 2 * (a + b), where a is the length, b is the width. Let’s calculate what the width of the rectangle is, knowing that the perimeter is 18 centimeters and the length is 6 centimeters.

1) (6 + x) * 2 = 18;

6 + x = 18/2;

6 + x = 9;

x = 9 – 6;

x = 3 cm.

2) b = 18/2 – 6 = 9 – 6 = 3 cm.

Answer: 3 centimeters.