How do you determine the area of a triangle?
A = 1/2 b*h[br][math]A=\frac{1}{2}b\cdot h[/math]
The volume of any figure can be given by V = A * L where A = the area of the base.
Think of the triangle as the base of this figure, what is the volume formula for the volume of a triangular prism?
[math]V=\frac{1}{2}b\cdot h\cdot l[/math]