Drawing Some Plane Curves Using Envelopes of Lines
An alternative to drawing a curve by plotting points is to draw it as the envelope of its tangent lines. Some of the envelopes in this Demonstration have applications in string art.
This was a project for Advanced Topics in Mathematics II, fall 2016, Torrey Pines High School, San Diego, CA.
 T. Iwamoto. "Lines and Circles." (Feb 1, 2017) www.takayaiwamoto.com/Lines_Circles/Lines_Circles.html#hypocycloid.
 A. Rossiter. "String Art." (Feb 1, 2017) www.antiprism.com/album/865_string _art/index.html.