The first wire shape is a square which has four equal sides and each side is 5 inches long. We multiple the number sides by the length of one (because it’s a square). This would be 5 x 4 which equals 20. The total length of the wire is 20 inches. The rectangle has 2 sides of 6 inches. That’s a total of 12. Subtract 12 from the total wire length. We get 8. Divide this by 2 to get the length of the other 2 sides.
Your answer is 4.