Question

The triangles shown have the same perimeter. What is the value of x?

Answer 1

18

Explanation:

Since you know the perimeters are equal, write your equation.

x+6 + x+6 + x+6 = x + x+6 + 2x-6

combine like terms

3x + 18 = 4x

isolate your x by subtracting 3x from each side

18 = x

check your answer:

3x + 18 = 72

4x = 72