Ihave 3 flower vases. my daughters sent me flowers. the packet of cut flower food that came with the flowers says to add 1/2 gallon of cool water. i want to fill the vase at least half before adding the flowers, but no more than 3/4 full before adding the flowers. (231 cubic inches = 1 gallon)

which vase would be best to use?

my vases are:

a cylinder with a diameter of 8" and 8" tall

a rectangular prism that is 4" by 5" and 10" tall

a triangular prism with a height of 10". the triangular base has a height of 6" and a base of 3"

which vase do i use? justify your answer.