I am looking to make the base of the trapezoid act as a drain pan. I was not able to figure out the form tool, which I feel is what I need to accomplish this. The idea is to recess the bottom to act as a funnel. If there is a better way, let me know. I have attached the drawing. I have completed the drawing, but forgot to add this in the beginning which is why it is rolled back. Thank you for you help.