Replying to Geometry Project involving Pitches of Jumps

I know there was a thread a while back on the angle of takeoffs and landings, but I didn't know what to search, I think it was made by Bishop.

Also if you have any knowledge on pitches of your local hill's runs and their rating (circle, square, etc.)  I need this for a geometry project.    My topic is how the average pitch of a slope, since the pitch does change as the run progresses, and the relationship to if the mid west's or east's double diamond is the same as a west coasts double diamond-being that I used to ski in the east and now live in the west and have noticed a difference.  Thanks to all!