For me, at least, graphics was the way to learn trig in the first place. I wanted to make a thingy on the screen go at a specified angle at a specified speed, so that I could change its angle without changing the speed, and I vaguely knew that this had something to do with sine and cosine, so I took a trig textbook off the shelf and puzzled it out. Didn't need things like the double-angle formulas, though, so I didn't learn those until I took a class that covered them.

Nice to hear. Go ahead and do write a program. If you have any issues with it, or have trouble following anything that is written in the article, send me an email and I'll be happy to help you out.

Totally agree. I recently had to do the same thing (relearning H.S. trig) using the HTML5 canvas.

It would be an interesting exercise to take this example and add a draw_arc() function.