Figuring out metal seam roof

[Jud Lang]

I am building a tiny home that is 28' x 10' with 3 degrees of angle. I am trying to figure out if the dimensions the guy at the roofing company gave me are correct (I have attached them here). I would like 6 inches of hang just to be safe. He is also wanting to know what the pitch for the trim would be and Im not sure how to figure that out. Any help would be much appreciated.