Find the third side of an isosceles triangle if the lengths of the other two sides are 5 cm and 2 cm.

In an isosceles triangle, the sides are equal in length. The problem is given two sides, one of which is lateral, the other is the base.

To determine which side of the triangle is lateral, we use the rule:

The sum of the lengths of the two sides of the triangle is greater than the third side.

Suppose that the length of the sides is 2 cm: a = b = 2 cm, base c = 5 cm, then

a + b> c;

2 + 2> 5;

4> 5.

The inequality turned out to be incorrect, the length of the sides cannot be equal to 2 cm.

The third side of the triangle is 5 cm.