Answer:
V=1526.82 mi³
Explanation:
The formula for the volume of a right circular cone is V=πr²(h/3).
The radius is half of the diameter of 18, so it is 9 mi.
The height is 18 mi.
Plug in your numbers into the formula.
V=π9²(18/3)
V=π81(6)
V=π486
V=1526.82 mi³