Question

The length of the base of the isosceles triangle is x. The length of a leg is 2x-2. The perimeter of the triangle is 21. Find x.

Answer 1

Answer: x=5

Explanation:

isosceles triangles consist of a base side and two congruent legs

if the length of the base is x and the leg is 2x-2, the other leg must also be 2x-2

the lengths of the sides of the triangle are x, 2x-2, 2x-2

the perimeter, the total length of the sides, is 21

x+2x-2+2x-2=21

5x-4=21

5x=25

x=5