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.



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