Constructing an angle’s trisectors

I really enjoyed this video about how to trisect angles. Trisection of arbitrary angles is impossible using only a straightedge and compass; however, it is possible by carefully folding a piece of paper.

For further reading:

Click to access amer.math.monthly.118.04.307-hull.pdf

Constructing a regular pentagon

One of my former students at UNT put together this fabulous interpretative dance for constructing a regular pentagon using straightedge and compass.