In a triangle, one side 12 cm, the second side is 115% of the first, and the perimeter is 300%

In a triangle, one side 12 cm, the second side is 115% of the first, and the perimeter is 300% of the first. Find the unknown side of the triangle.

Let’s calculate the second side of the triangle:

12 * 115/100 = 12 * 1.15 = 13.8 cm;

Let’s calculate the perimeter of the triangle from the first side:

12 * 300/100 = 12 * 3 = 36 cm;

Find the unknown side of the triangle by subtracting two known sides from the perimeter:

36 – 12 – 13.8 = 10.2 cm.

Answer: the third side is 10.2 cm.