To answer this question you need to know how to find the volume of a trapezoidal prism. You multiply the area of a trapezoid by the height of the prism. To begin answering this, you can start with 2 different factors of 120. I chose 4 and 6.
If the height of one trapezoid is 4, the area would need to be 30. I wrote out the formula for area of a trapezoid (h (b1+b2)/2) and solved for 30. I multiplied both sides by 2 and saw that I needed a 60 from the sun of my 2 bases and the height of the trapezoid base. I used 2 for the height and 20 and 10 as the 2 bases.
For the second trapezoid, I used 6 as the height of the prism. This left me with 20 as the area. I used the same formula above and found that I needed to get 40. I used 5 as the height of the trapezoid and 1 and 7 as the two base lengths. Hope this helps!!