The perimeter of an isosceles triangle ABC is 17 cm. Find the length of the base AC if AB = 5?

The perimeter of an isosceles triangle ABC is found by the formula:

P = 2 * a + b, where a is the sides of the triangle, which are equal to each other, b is the side of the base of the triangle.

We know the value of the lateral side of the triangle, then, knowing the value of the perimeter, we find the length of the base of the AC of an isosceles triangle:

2 * a = 2 * 5 cm = 10 cm;

17 cm – 10 cm = 7 cm.

P ABC = 5 cm + 5 cm + 7 cm = 17 cm, or:

P ABC = 2 * 5 cm + 7 cm = 10 cm + 7 cm = 17 cm.

Answer: The length of the base of the AC = 7 cm.