Answer:
The area of the base is 120.39 ft²
Explanation:
To calculate the area of a rectangular prism we have to use the following formula: 
a = area 
v = volume = 2167ft³
h = height = 18ft
 
v = a * h 
 
we replace the known values and solve
 
 2167ft³ = a * 18ft
 2167ft³ / 18ft = a * 18ft /18ft
120.39 ft² = a
 
The area of the base is 120.39 ft²