I have no clue the angle for the corners. I am using an electric Compound miter saw.I did see in handyman that they have jigs for varying sizes of crown, but I doubt it's ness.If interested check it out. www.mitermaster.com Is it nesesary to cope an angle for a corner joint? What is the angle for a 90 deg. corner? I'm cutting 3 3/8 stock. Thanks for your input.