Getting ready to introduce trig functions I opened the first lesson from last year and found this horror show.
Many thanks to Dan Meyer for the upgrades to my supposedly-educational crapola radar. (Don't you love how the textbook labels this "Egyptology" for us? That adds so much awesomeness to this problem. It really enhances the pixellated image.)
Now I don't really want to spend 30 minutes rehashing right triangle trig, just remind them about it before I peg a vertex to the origin and one side to the x-axis and start spinning the hypotenuse around. As of now I'm at the filtering-signal-from-noise stage of devising something better.