One of the sides of an isosceles triangle is 18 cm, and the other 8 cm. Find the base.

It follows from the condition of our problem that the triangle is isosceles. This means that the basis can be equal in theory to either of the two known sides.

Let’s consider both options.

Option number 1 (the base is 8 centimeters).

Then we check, according to the property of the sides of the triangle:

18 + 8> 18;

18 – 8 <18;

18 – 18 <8;

18 + 18> 8 (this option is possible).

Option number 2 (the base is 18 centimeters).

Then we check, according to the property of the sides of the triangle:

8 + 8 <18 (this is not possible).

Answer: 8 cm.