The perimeter of the rectangle is 40m, the area is 36 square meters, find the sides of the rectangle

1. We take for x (m) the length of the rectangle, for y (m) its width.

2. Let’s compose a system of two equations:

(1) 2 (x + y) = 40; x + y = 20; x = 20 – y;

(2) x x y = 36;

3. Substitute x = (20 – y) into the second equation:

(20 – y) y = 36;

20y – y² = 36;

y² – 20y + 36 = 0;

The first value of y = (20 + √400 – 144) / 2 = (20 + 16) / 2 = 18 m.

The second value is y = (20 – 16) / 2 = 2 m.

The first value is x = 20 – 18 = 2m.

The second value is x = 20 – 2 = 18 m.