Creation of this applet was inspired by a [url=https://twitter.com/gogeometry/status/952380626648424448]tweet[/url] from [url=https://twitter.com/gogeometry]Antonio Gutierrez[/url] (GoGeometry). [br][br][b][color=#ff00ff]You can control the size of the pink angle by adjusting the pink slider.[/color][/b] [br]You can move any of the [b]LARGE POINTS[/b] anywhere you'd like at [b]ANY TIME.[/b][br][br][b][color=#38761d]How would you describe the phenomenon dynamically illustrated here? [br]How can we formally prove this true? [/color][/b]