The perimeter of a rectangle is 20cm, its side length is 6cm, find the width of the rectangle?

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. We calculate what the width of the rectangle is, knowing that the length is 6 centimeters and the perimeter is 20 cm.

(b + 6) * 2 = 20;

b + 6 = 20/2;

b + 6 = 10;

b = 10 – 6;

b = 4 centimeters.

Answer: 4 centimeters.