The side of an isosceles triangle is 5 times the base, and the perimeter of this triangle is 99. Find all sides of the triangle.

We draw up an equation in which we write the value of the length of the base of an isosceles triangle as x cm.

Since the lateral side is 5 times larger than the base, its length will be: 5 * x cm.

Since the perimeter of a triangle is the sum of its sides, we get the following equation:

x + 5 * x + 5 * x = 99.

11 * x = 99.

x = 99/11 = 9 cm (base).

5 * x = 5 * 9 = 45 cm (side).

Answer: 9, 45 and 45 cm, respectively.