Check this well-produced rap by Montgomery Blair math teacher Jake Scott. Cool!
Good job, Mr. Scott! We’ll look forward to more videos!
*one small issue: I hope students aren’t confused by the sliding of a circle to form the sine/cosine graph. It might be a bit misleading.
Random Walks 
Point well taken about the circle to the sin curve. I thought about that as I was making the video but could not think of a better illustration in the 60 minutes that I took to make the video. I thought about string but: 1. I could not get a perfect circle and the transition was too difficult without my hands getting all in the way. I tried to find an animator but could not. I hope the color coded poster clears it up.
SPECIAL RIGHT TRIANGLES VIDEO