# Side AB of triangle ABC is 5 cm. Side BC is twice as large as side AB.

**Side AB of triangle ABC is 5 cm. Side BC is twice as large as side AB. The side is 2 cm less than the BC side. Find the perimeter of the triangle.**

Let’s find the length of the side BC of the given triangle ABC.

According to the condition of the problem, the AB side of this triangle ABC is 5 cm, and the BC side is twice as large as the AB side, therefore, the length of the BC side is:

| BC | = 5 * 2 = 10 cm.

Find the length of the AC side of this triangle.

According to the condition of the problem, the AC side is 2 cm less than the BC side, therefore, the AC side length is:

| AC | = 10 – 2 = 8 cm.

Let’s find the perimeter of a given triangle as the sum of the lengths of all sides of this triangle:

| AB | + | BC | + | AC | = 5 + 10 + 8 = 15 + 8 = 23 cm.

Answer: the perimeter of this triangle is 23 cm.