The perimeter of a rectangle is 36 cm, the sum of the lengths of its 3 sides is 25 cm. What is the area of this rectangle?

1) How long is the first side of the rectangle?

36 – 25 = 11 (cm)

2) What is the second side of the rectangle?

Let’s denote the second side by x cm.

Let’s compose and solve the equation:

(x + 11) * 2 = 36;

x + 11 = 36: 2;

x + 11 = 18;

x = 18 – 11;

x = 7.

The second side of the rectangle is 7 cm.

3) What is the area of the rectangle?

7 * 11 = 77 (cm2).

The answer is the area of the rectangle is 77 cm2.