Which equation can be used to find the answer?   A playground with four sides has a perimeter of 52 ft. Three of the sides have lengths of 9 ft, 16 ft, and 19 ft. What is the length of the fourth side? 	 	   A. 	  s – 9 + 16 + 19 = 52   s =26   26 ft 	   B. 	  s + 9 + 16 + 19 = 52   s = 8   8 ft 	   C. 	  s – 52 = 9 + 16 – 19   s = 58   58 ft 	   D. 	  s – 9 – 16 – 19 = 52   s = 96   96 ft