The perimeter of the rectangle is 170 cm and the width is 20 cm less than the length. Find the length 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. Let the width be – x cm, then the length is equal to x + 20 cm. Knowing that the perimeter is 170 centimeters, we will make an equation.

2 * (x + x + 20) = 170;

2x + 20 = 170/2;

2x + 20 = 85;

2x = 85 – 20;

2x = 65;

x = 65/2;

x = 32.5 cm.

The length of the rectangle is 20 + 32.5 = 52.5 cm.

Answer: 52.5 centimeters.