The perimeter of the triangle is 54 cm, and one of the sides is 20 cm.Find the other two sides if the difference is 6.2 cm.

From the condition it is known that the perimeter of the triangle is 54 cm, and one of the sides is 20 cm. It is also known that the difference between the other two sides is 6.2 cm.

In order to find two unknown sides of a triangle, we compose and solve a linear equation.

Let’s apply the formula for calculating the perimeter of a triangle to compose an equation:

P = a + b + c;

let the second side be x cm, then the third can be written as (x + 6.2) cm. As a result, we get the equation:

20 + x + (x + 6.2) = 54;

2x = 54 – 26.2;

2x = 27.8;

x = 13.9 cm and 13.9 + 6.2 = 20.1 cm of the side of the triangle.