Construct a pentagon

This is where mathemagic gets tricky! This is not the only way to construct a pentagon, but I think it is pretty elegant.

I colorcoded the steps - do purple, then blue, then red. I've marked the centers of arcs with x's, and only drawn the arcs instead of the whole circle where I didn't need the whole thing.

This method uses pairs of arcs with equal radii to bisect angles and draw lines at right angles.

Enjoy!

For a cool animation of this, check out the wikipedia page:

http://en.wikipedia.org/wiki/Pentagon#Construction