The perimeter of the triangle is 3dm 5cm. The length of the first side of the triangle is 8cm, the length of the second side

The perimeter of the triangle is 3dm 5cm. The length of the first side of the triangle is 8cm, the length of the second side is 1dm 5 cm. Find the length of the third side of the triangle.

Let’s translate all known values into a single measurement system, in centimeters.
As you know, the perimeter of a triangle is the sum of all sides, and is calculated by the following formula: P = a + b + c.
From the problem statement, we know: the perimeter P = 35 cm, one side a = 8 cm, the other side b = 15 cm.
Substitute all the known values of the sides and perimeter of the triangle in the formula and find the third side: 35 = 8 + 15 + s.
35 = 23 + p.
c = 35 – 23 = 12 cm.
Answer: The length of the third side of the triangle is 12 cm.