The length of base of an isosceles triangle is x. The length of a leg is 4x-4. The perimeter of the triangle is 100. Find x

12

Explanation:

Given parameters

Base of the isosceles  = x

Length of leg  = 4x - 4

Unknown:

Perimeter of triangle  =100

Unknown:

The perimeter of a triangle is the sum of its sides;

   An isosceles triangle has two equal length of leg;

        So;

        x + 2(4x - 4) = 100

        x + 8x -8  = 100

           9x - 8  = 100

            9x = 100 + 8

             9x = 108

               x = 12