The perimeter of a triangle if the length of one side is 7 cm, the length of the second is 13 cm

| September 14, 2021 | education

The perimeter of a triangle if the length of one side is 7 cm, the length of the second is 13 cm, and the third side is shorter by 3 cm.

It should be said that the perimeter of a triangle is equal to the sum of all its sides. That is:

P = a + b + c, where a, b, c are the sides of the triangle; P is the perimeter of the triangle.

We do not know of any third party. By the condition of the problem, it is known that its length is shorter by 3 cm. But we do not know whether the third side is shorter by 3 cm relative to the first or the second side. Therefore, we will consider two solutions. The first of them – the third side is shorter than the first by 3 cm:

Then c = a – 3 = 7 – 3 = 4 cm. And the perimeter is: P = a + b + c = 7 + 13 + 4 = 24 cm;

For the second case:

c = b – 3 = 13 – 3 = 10 cm;

P = a + b + c = 7 + 13 + 10 = 30 cm.



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