the volume of the triangular prism will be, the area of the triangular face times its length
[tex]\stackrel{\textit{area of the triangle}}{\left[ \cfrac{1}{2}(\underset{b}{8})(\underset{h}{8}) \right]}~~ ~~\stackrel{length}{(x)}~~ = ~~\stackrel{volume}{576}\implies 32(x)=576 \\\\\\ 32x=576\implies x=\cfrac{576}{32}\implies x=18[/tex]
