Answer:
x=6
Step-by-step explanation:
the perimeter of the rectangle is equal to 2x + 16.
the perimeter of the triangle is equal to 3x + 10.
since they are equal now you can solve by saying 2x + 16 = 3x + 10
Now you solve for x
2x + 16 = 3x + 10
2x + 6 = 3x
6 = x