One side of the triangle is 25 cm, the other is 4 cm longer than the first, and the third is 4 cm

One side of the triangle is 25 cm, the other is 4 cm longer than the first, and the third is 4 cm shorter than the first, which is equal to the perimeter of the triangle.

It is easy to find that a triangle has sides: 25 cm, 25 cm + 4 cm = 29 cm and 25 cm – 4 cm = 21 cm. At first glance, the task requires solving a very simple trigonometry problem: the perimeter of a triangle is the sum of three sides; one side is 25 cm, the other is longer, and the third is shorter by the same amount, therefore, the perimeter is 3 * 25 cm = 75 cm.
As a note, I would like to note that if in the task instead of “4 cm” they would write, for example, “14 cm”, then the answer “75 cm” would be erroneous, since there is no triangle with sides of 25 cm, 39 cm and 11 cm …
For the sake of confidence, for a triangle with sides of 25 cm, 29 cm and 21 cm, check the property: “In any triangle, the half-perimeter is larger than any side.” The semi-perimeter is (75 cm): 2 = 37.5 cm. Indeed, 37.5> 25; 37.5> 29 and 37.5> 21. It’s okay.
Answer: 75 cm.