The perimeter of triangle ABC is 16 cm, side AB is 3 cm less than side AC.Find the length of side BC if AC = 7 cm.

The perimeter of a triangle is equal to the sum of its three sides. To answer the question of the problem, you need to know the length of the side AB.
1. Let’s calculate what is the side AB of triangle ABC.
7 – 3 = 4 centimeters.
2. Let’s find what is the sum of the side AB and the side AC of the triangle ABC.
7 + 4 = 11 centimeters.
Let’s answer the question of the problem.
3. Let’s define what is the length of the BC side.
16 – 11 = 5 centimeters.
Answer: The length of the BC side of the ABC triangle is five centimeters.