So Perimeter is 256 and since that is side + side + side + side then it would be 256 / 4 but since we have a requirement, its different.
we need 16 extra on length so 2 sides that makes 32. if you subtract 32 from 256 you get 224 if you divide that by 4 you get the sides minus the 16 on the top and bottom making the answer 56