The perimeter of an isosceles triangle is 28 cm, and the lateral side is 10 cm, find the base of the triangle.

The perimeter of a triangle is the sum of the lengths of all its sides. The side in an isosceles triangle is called the base and the other two are called the sides. The sides in an isosceles triangle are equal. Then the first action is to find the sum of the sides.
1) 10 + 10 = 20 (see) the sum of the lengths of the sides; We know the perimeter of an isosceles triangle. Let’s find what the base will be equal to. To do this, subtract the sum of the lengths of the sides from the perimeter:
2) 28 – 20 = 8 (see) the length of the base of an isosceles triangle.
Answer: 8 centimeters