Make a ramp - anything will do, a piece of cardboard, a VEX 5x25 metal, a piece of flat plastic. Put a disc on the floor. Hold the ramp like you do in the drawing. Push the disc into it. When the disc starts climbing up the ramp that’s your answer. Hint - edge of disc is round. Account for the fact that whatever you test on the kitchen table is a bit different from the field because robot wheels sink into tiles a bit. Document the whole experiment in the notebook.
Test moving the flat piece of something back and forth once u find your angle to make sure its not scraping against the floor. More data for your notebook too.
Make sure not to scrape the floor, i nearly got disqualified because i had some forks tearing up the new mats.