I am seeking assistance on how to create intersecting polygon(s) that is/are derived from 100ft vertical set back from the ridgeline. Basically, I have been tasked by our Planning Dept. to show deviation of 25% slope, ridgeline, and 100ft vertical set back from the ridgeline of our surround terrain. My dilemma is how to create the vertical 100ft set back and determining the intersecting points and/or polygons on the terrain. Please see attached pic. Hopefully the pic can explain what I need to figure out. Thank you.