The perimeter of the rectangle is 54m. Find the area by a rectangle if one side is 18m.

It is known from the condition that the perimeter of the rectangle is 54 meters. In order to find the area of a rectangle, if one side of it is 18 meters, we first calculate the length of the second side of the rectangle.

To do this, we will compose and solve a linear equation using the formula for finding the perimeter of a rectangle.

P = 2 (a + b);

2 (18 + x) = 54;

18 + x = 54: 2;

18 + x = 27;

x = 27 – 18;

x = 9 meters is the length of the second side of the rectangle.

Let’s remember the formula for finding the area of a rectangle:

S = a * b = 18 * 9 = 162 m2.