The perimeter of the rectangle is 22 cm. Find its sides if you know that the area of the rectangle is 28 cm ^ 2.

1. A, B, C, D – the vertices of the rectangle.

2. We take as x (cm) the length of the side AB, for y (cm) the length of the side AD.

3. Let’s compose two equations:

(1) 2x + 2y = 22; x + y = 11; x = 11 – y;

(2) xy = 28;

4. Substitute the value x = (11 – y) into the second equation:

(11 – y) y = 28;

11y – y² = 28;

y² – 11y + 28 = 0;

The first value y = (11 + √121 – 28 x 4) 2 = (11 + 3) / 2 = 7 cm.

The second value is y = (11 -3) / 2 = 4 cm.

The first value is x = 11 – 7 = 4 cm.

The second value is x = 11 – 4 = 7 cm.

AB length can be 4 cm or 7 cm.

The length of blood pressure can be 7 cm or 4 cm.

Answer: AB length can be 4 cm or 7 cm, AD length can be 7 cm or 4 cm.