Calculate the length of the sides of a triangle with a perimeter of 8.7 cm, if the first side is 0.4 cm longer than the second

Calculate the length of the sides of a triangle with a perimeter of 8.7 cm, if the first side is 0.4 cm longer than the second, and the second is by the same amount more than the third.

1. By the condition of the problem, it is known that the perimeter of the triangle is 8.7 cm, one side is 0.4 cm larger than the second, which in turn is 0.4 cm larger than the third.

Let’s denote the length of the first side as x cm.

2. Let’s define an expression for the second one:

x – 0.4 cm.

Let’s write the value of the third:

(x – 0.4) – 0.4 cm

Let’s make the equation

x + (x – 0.4) + (x – 0.8) = 8.7;

3 x – 1.2 = 8.7;

3 x = 8.7 = 1.2 = 9.9; whence x = 9.9: 3 = 3.3 cm.

The length of the second side is 3.3 cm – 0.4 cm = 2.9 cm.

For the third, the value is 3.3 cm – 0.8 cm = 2.5 cm.

Answer: The sides of the triangle are 3.3 cm, 2.9 cm, 2.5 cm.