In an isosceles triangle, one side is 25 cm and the other is 10 cm. Which of these sides is the base?

So, in an isosceles triangle, one side is 25 cm, and the other is 10 cm. In order to find which side is the base, let’s recall the conditions under which the triangle can exist.
A triangle exists if the sum of the lengths of the two sides of the triangle is always greater than the third.
If the base is 25 cm, then the sides are 10 cm.
10 + 10 <25 (condition is not met).
If the base is 10 cm, and the sides are 25 cm, then
25 + 25> 10;
10 + 25> 25, the condition is met.
Answer: the base is 10 cm.