Answer:
45 feet width
Step-by-step explanation: 4 fences required as given as one is already along the side of building and says 'fencing in '
40 ft lengths = 40 *2 = 80ft playground perimeter of only the lengths and then the widths is looked for so we label 40 feet length on rectangle Then ; (( perimeter subtracted by 2 lengths) /the amount of widths) = ((170-80) /2) = 90/2 = 45 feet =width then label width 45 feet