One side of the triangle is equal to 3dm 6cm. The second side is 18 cm shorter.

One side of the triangle is equal to 3dm 6cm. The second side is 18 cm shorter. The third is twice as long as the other. Find the perimeter of the triangle.

1. According to the data presented in the problem statement, the length of the first side in a given triangle is 3 dm 6 cm or 36 cm.

2. Calculate the length of the second side of the triangle if we also know that it is 18 cm shorter than the first side.

36 – 18 = 18 cm.

3. Now define the length of the third side, which is 2 times longer than the length of the second side.

18 * 2 = 36 cm.

4. Now let’s calculate what the perimeter of this triangle is equal to by adding the lengths of all its sides.

P = 36 + 18 + 36 = 90 cm.