Creation of this resource was inspired by a [url=http://www.gogeometry.com/school-college/3/p1225-equilateral-triangle-bisector-circle-congruence.htm]problem[/url] posted by [url=https://twitter.com/gogeometry]Antonio Gutierrez[/url] (GoGeometry). [br][br][b]LARGE POINTS[/b] are [b]MOVEABLE[/b] at any time. [br][br]How would you describe the phenomena you see in your own words?[br](Try to do so first [i]without[/i] opening the problem link in another tab). [br][br][b]How can we formally prove all that is dynamically illustrated here? [/b]