Mod note: Moved from a Homework section, as this is more of a conceptual question than an actual homework problem. I can't really memorize the unit circle, but I do remember my instructor teaching us how to use reference angles to evaluate any trig function without needing the unit circle. I was wondering if anyone remembers this method? I tried to google it but couldn't really find any good results on the topic. I know we had to memorize three triangles for a 45, 60, 90 degree angles, but I'm a bit lost after that. @Sparkle, if you post a question in the Homework sections, you must use the homework template.