Find the perimeter of the triangle, if AB = BC = 5, and AC is more than AB by 20%?

First, let’s find the length of the AC side of this triangle ABC.

In the initial data for this task, it is reported that the length of the AC side is 20% greater than the length of the AB side.

According to the condition of the problem, the length of the AB side is 5, therefore, the length of the AC side is:

5 + (20/100) * 5 = 5 + (2/10) * 5 = 5 + 0.2 * 5 = 5 + 1 = 6.

Knowing the lengths of all sides of a given triangle, we can calculate its perimeter p:

p = | AB | + | BC | + | AC | = 5 + 5 + 6 = 10 + 6 = 16.

Answer: The perimeter of this triangle is 16.