The area of the rectangle is 120 cm2, the length of one of its sides is 15 cm, the perimeter of this rectangle is calculated.

It is known from the condition that the area of the rectangle is 120 cm2. And it is also known that one of the sides is 15 cm. In order to find the perimeter of a rectangle, we must find its sides. To do this, we will compose and solve the equation.

Let us denote the unknown side by the variable x.

Let’s compose and solve the equation using the area of a square formula:

S = a * b;

15x = 120;

x = 120: 15;

x = 8 cm; the length of the second side.

Let’s remember the formula for finding the perimeter and calculate the perimeter of the rectangle:

P = 2 (a + b) = 2 (15 + 8) = 2 * 23 = 46 cm.