First, let's find the area of the triangle:
[tex]A=\dfrac{1}{2}bh=\dfrac{1}{2}\times3\times4=6[/tex]
Now, we multiply this area by the length of the prism, which is 20
[tex]20\times6=120[/tex]
All 3 answers have 120. However, since we're calculating volume, it will be represented by [tex]\text{units}^3[/tex]. Since no specific unit (such as cm or in) is specified, it will be left at that.
Thus, the answer is answer choice D.
Let me know if you need any clarifications, thanks!
