I am always looking for ways to find artsy activities to use in math class, and this year I found this one that I used in the trigonometry unit of my pre-calculus class. I totally stole it from someone else, and tweaked it a bit, but the kids really enjoyed it, and it helped them see the reference angle relationships better. Plus, we did it right around Christmas, so my room was full of colorful trig ornaments! Our final products looked like this: Here is the link for the instructions Unit Circle Pie Plate instructions Enjoy!