We can use formula of volume of cylinder to calculate volume of silo.
[tex] Volume\; of \; cylinder = \pi r^2 h [/tex]
Plug the given values of radius r=7 ft and height h= 33 ft
[tex] Volume\; of \; cylinder = \pi (7)^2 (33) [/tex]
[tex] Volume\; of \; cylinder = \pi (49) (33) [/tex]
[tex] Volume\; of \; cylinder = \pi (1617) [/tex]
So the required volume of silo is [tex] 1617 \pi [\tex]