Find the base of an isosceles triangle if its side is 17 cm and its perimeter is 54 cm.

In the condition, we are given an isosceles triangle. The length of the lateral side is known – 17 cm, and the perimeter of the triangle is 54 cm.

In order to find the base of a triangle, we’ll start by remembering how to find the perimeter of a triangle.

P = a + b + c;

The sides of an isosceles triangle are equal to each other. So we can write the perimeter as P = 2a + c;

Let’s denote the base for x and get the equation:

2 * 17 + c = 54;

34 + c = 54;

c = 54-34;

c = 20 cm base of the triangle.

Answer: 20 cm.