Creation of this applet was inspired by a [url=https://twitter.com/gogeometry/status/950752529616384000]tweet[/url] from [url=https://twitter.com/gogeometry]Antonio Gutierrez[/url] (GoGeometry). [br][br]You can alter the size of each colored angle by its respective colored slider at any time. [br]LARGE POINTS are also moveable at any time. [br][br][b][color=#ff00ff]How can we formally prove what is dynamically illustrated here? [br][/color][/b]