lip on top of the ramp?
 

We are building a practice ramp and need to know the exact length of the lip on top of the hill. How tall is the lip?

Well, my first caution is, don't build anything tht requires that tight of tolerances. There could be small variations in the lip from event to event, or from your practice field to the competition field. If you build a robot with 1/16" tolerances, and it's off by 1/8", you'll be in trouble. That being said, I believe that the lip on top was 1/2", though this is just from memory.

The lip is 3/8 inch
 

Yep.