Please need help with this

So first we need the formula for a triangular prism
[tex]v = ( \frac{1}{2} bh)h[/tex]
Which, since we have all of our number for base, and both heights, we can plug it intk our formula
[tex]v = (\frac{1}{2} \times 15 \times 8) \times 17[/tex]
When we calculate it, it comes out to be 1020 cubuc feet.