Answer:
739 x 4
2926 ft³ is your answer
Step-by-step explanation:
radius=18/2=9 ft
[tex]V=\frac{4}{3} \pi r^3\\=\frac{4}{3} \pi (9)^3\\\approx \frac{4}{3} \times 3\times 729\\\approx 4 \times 729\\\approx 2916 ~ft^3[/tex]