Which equation can be used to find the answer?

a playground with four sides has a perimeter of 73 ft. three of the sides have lengths of 14 ft, 19 ft, and 25 ft. what is the length of the fourth side?

a.
s + 14 + 19 + 25 = 73
s = 15
15 ft

b.
s – 14 + 19 + 25 = 73
s =43
43 ft

c.
s – 73 = 14 + 19 – 25
s = 81
81 ft

d.
s – 14 – 19 – 25 = 73
s = 131
131 ft