Question

The length of the base of an isosceles triangle is x. The length of a leg is 5x-5. The perimeter of the triangle is 144 . Find x.

Answer 1

Explanation:

isoceles triangle means that both legs have the same length.

the perimeter is the whole way around the triangle once (the sum is all 3 sides).

so, we know the specification of all 3 sides :

x

5x - 5

5x - 5

and we know the perimeter : 144.

so,

144 = x + (5x - 5) + (5x - 5) =

= x + 5x - 5 + 5x - 5 = 11x - 10

154 = 11x

x = 154/11 = 14