The perimeter of an isosceles triangle is 21 cm. The base of the triangle is 3 times shorter

The perimeter of an isosceles triangle is 21 cm. The base of the triangle is 3 times shorter than its lateral side. Find the length of each side of the triangle.

From the condition it is known that the perimeter of an isosceles triangle is 21 cm. We also know that the base of the triangle is 3 times less than the length of its lateral side.

Let’s denote by x cm the length of the base of an isosceles triangle, then the length of the lateral side is 3x cm.

From the definition of an isosceles triangle, it is known that the lengths of the sides are equal.

Perimeter of an isosceles triangle:

P = 2a + b;

2 * 3x + x = 21;

6x + x = 21;

7x = 21;

x = 21: 7;

x = 3.

3 cm at the base of the triangle and 3 * 3 = 9 cm in the length of the sides.