Comment by nyc111

Norman Wildberger has an alternative system for trigonomtry:

Understanding uniform motion: are radians really necessary? | WildTrig

https://youtu.be/CnQXRdgN_7I?si=EiYY99i6mBOIyczI

Wild Trig: An introduction to Rational Trigonometry

https://youtube.com/playlist?list=PLIljB45xT85CyF_7bKd6y36VA...