You can put this solution on YOUR website! length of window = 5 ft 2 in
width = 3 ft 5 in
perimeter = 2*( length+width)
= 2*(5ft 2 in +3 ft 5 in)
= 2*(8 feet 7 in)
= 2*8 feet +2*7 inches
= 16 feet +14 inches
but 12 inches = 1 foot
= 16 feet +12 inches+2 inches
= 16feet+1 foot + 2 inches
= 17 feet 2 inches
Result : Perimeter = 17 ft 2 in