well ur working with perimeter and its a square remember all sides will be the same so u would divde 250 and 125 from 4 so 250/4=62.5 and 125/4=31.25. so now u find that now hr taking away both of the perimeters cause ur finding how much GREATER so that will be 62.5-31.25= 31.25 if u have any more problems and if u have instagram my ne on it is j.j.henry.