First you have to find the Area of the triangle:
[tex]A= \frac{1}{2} (b*h)[/tex]
So [tex]A= \frac{1}{2} (9*12)
[/tex], which is [tex]54[/tex]
Now multiply that by the Height of the Triangular Prism:
[tex]V=54*10[/tex], which is equal to 540
Final Answer: [tex]V=540[/tex]