One side of the rectangle is twice the size of the other, and its perimeter is 36 cm. What is the smaller side of the rectangle?

Because the sides of the rectangle are unknown, we denote that the width of the rectangle is x cm, then the length is 2x cm, because according to the condition of the problem, one side of the rectangle is twice as large as the other. Let’s write the equation:

(x + 2x) * 2 = 36;

3x = 36: 2;

3x = 18;

x = 18: 3;

x = 6 (cm) – the width of the rectangle;

If the width of the rectangle is 6 cm, then the length of the rectangle will be 2 * 6 = 12 cm.

The smaller side of the rectangle will be 6 centimeters.

Answer: 6 centimeters.