Creation of this applet was inspired by a [url=http://www.gogeometry.com/ArchBooLem08.htm]post[/url] from Antonio Gutierrez ([url=http://www.gogeometry.com/]GoGeometry[/url].) [br][br][b][color=#ff00ff]Move the LARGE PINK POINT anywhere you'd like (along the circle). [/color][/b][br][br][b][color=#0000ff]How can we formally prove what this applet informally illustrates? [/color][/b]

Some ancient Greek mathematicians used this method to trisect an angle. Can you see why?[br][br]For more information, see this [url=https://en.wikipedia.org/wiki/Neusis_construction]Wikipedia article[/url].