Hello from MrBillDoesMath!
Answer: 3
Discussion:
The perimeter of a polygon is the sum of the side lengths.
Perimeter of top polygon is (x+2) + 2x + (x + 2) + (4x + 1) = 8x + 5
Perimeter of bottom triangle is 4x + 2x + (3x+2 ) = 9x + 2
The perimeters are the same when
8x + 5 = 9x + 2
Subtract 8x from both sides:
5 = (9x - 8x) + 2 or
5 = x + 2
Subtract 2 from each side to get x = 3:
5 -2 = 3 = x
The perimeter of either figure is 29
Regards, MrB