Creation of this resource was inspired by a [url=http://www.gogeometry.com/problem/p625_triangle_parallel_congruence_angle_bisector_online_geometry.htm]problem[/url] posed by [url=https://twitter.com/gogeometry]Antonio Gutierrez[/url] (GoGeometry). [br][br]You can move[b] LARGE POINTS [/b]anywhere you'd like [b]AT ANY TIME[/b]. [br]You can also control the [b][color=#38761d]size of the green angle [/color][/b]by using the [b][color=#38761d]green slider[/color][/b]. [br][br][b][color=#ff00ff]How would you describe the phenomena you see in your own words? [/color][/b][br][b][color=#ff00ff][br]How can we formally prove what is dynamically illustrated here? [/color][/b]