45km : 30 min = 180km : x
x = = = 60*2 min = 120 min = 2h
Since the surface is 3 feet wide around the pool add 6 feet to both dimensions ( 3 feet x 2 = 6).
12 ft + 6 ft. = 18 feet
15 ft + 6ft. = 21 feet
Perimeter = 2L + 2W
Perimeter = 2(18) + 2(21)
Perimeter = 36 + 42
Perimeter = 78 feet.
A horizontal line test would show that the equation is a relation but not a function (C)