In an isosceles triangle, one of the sides is 6 cm, and the perimeter of the triangle is 20 cm.

In an isosceles triangle, one of the sides is 6 cm, and the perimeter of the triangle is 20 cm. find the rest of the sides of the triangle.

Option # 1 (the known side is the base of the triangle).

Let us determine through what number of centimeters the length of each of the lateral sides will be expressed, when from the condition of the task we know that the perimeter of our figure is 20 centimeters:

(20 – 6): 2 = 7.

Answer: Two sides of 7 cm.

Option # 2 (the known side is the side of the triangle).

Then the second side is also 6 cm.

Let’s determine what the base of the triangle will equal:

20 – 6 * 2 = 8.

Answer: One is 6 cm, the second is 8 cm.