u/Aurust

I'm wondering how I calculate what angle and bevel I need to cut to have two same sized board create a clean joint around a corner where one board is straight level and the other is sloped down at 22.5 degrees. Image shows what I am trying to do. I want to understand how to work this out so I can replicate in future cuts too. Thanks!

EDIT - Thanks for replies so far. Why I want to join like this is because it is exterior trim being used as a frieze board and one side of the trim has grooves that I want to try hiding from both sides.