The perimeter of the triangle is 186mm. The length of one side is 42mm, the second is twice as long

The perimeter of the triangle is 186mm. The length of one side is 42mm, the second is twice as long. What is the third side of the triangle?

Let the lengths of the sides of the triangle be a, b, c see.

By condition, a = 42 mm.

Determine the length of side b.

b = a * 2 = 42 * 2 = 84 mm.

Determine the length of the side with.

c = a – 3 = 13 – 3 = 10 mm.

The perimeter of a triangle is equal to the sum of the lengths of its sides.

P = a + b + c;

186 = 42 + 84 + с;

C = 186 – 42 – 84;

C = 60 mm.

Answer: The length of the third side is 60 mm.