How would you describe what you see into words? How can you [color=#9900ff][b]prove this phenomenon true[/b][/color], regardless of the location of the [b][color=#1e84cc]blue point[/color][/b]?
For more information, see this [url=http://www.gogeometry.com/school-college/2/p1166-triangle-circle-perpendicular-diameter-congruence-math.htm]post[/url] from Antonio Gutierrez ([url=http://www.gogeometry.com/]GoGeometry[/url]).