If square has a perimeter of 20 inches, the length of each side is:
After cutting the square in half, we are left with two rectangles of 5 in x 2.5 in
Attaching those two smaller rectangles by their short end (2.5 in side), gives us a new rectangle with a height of 2.5 in and a length of 10 in (sum of the 5 in sides in each rectangle). The perimeter of this new rectangle is: