the volume is calculated multiplying the width, height, and length:
v = whl
as we do not have much information about all those three, I will assume that the prism is a cube, therefore all sides are equal, call them s, so the volume would be:
v = whl = s*s*s = s^3
and plug in the data:
v = 576 = s^3
s = 576^(1/3)
s = 8.32
therefore each side of the cubic prism would have a length of 8.32 inches