Creation of this applet was inspired by a [url=http://www.gogeometry.com/problem/p776-triangle-isogonal-perpendicular-feet-concyclic-midpoint-plane-geometry.htm]post[/url] from Antonio Gutierrez ([url=http://www.gogeometry.com/]GoGeometry[/url]). [br][br][b]Note:[br][/b][br][color=#38761d][b]The green slider alters the size of the triangle's interior angle with green vertex.[/b][/color][br][b][color=#ff00ff]The white point adjacent the pink angle alters the size of this pink angle.[/color][/b][br][b]Any of the other BIG WHITE POINTS can be placed anywhere you'd like. [br][/b][br][color=#0000ff][b]How can we formally prove the phenomena dynamically illustrated here? [/b][/color]