Creation of this applet was inspired by a [url=https://twitter.com/gogeometry/status/881244362293878784]tweet[/url] from [url=https://twitter.com/gogeometry]Antonio Gutierrez[/url] (GoGeometry). [br][br][b][color=#ff00ff]You can alter the size of the pink angle (soon to appear) using the pink slider.[/color][/b][br][b]You can also move any of the BIG WHITE POINTS around at any time. [/b][br][b][color=#1e84cc][br]How would you describe the phenomena you see?[/color][/b][br][br][b][color=#1e84cc]How can we formally prove what this applet dynamically illustrates? [/color][/b]