Creation of this applet was inspired by a [url=http://www.gogeometry.com/school-college/2/p1138-square-circle-perpendicular-90-degrees-angle.htm]problem[/url] posted by [url=https://twitter.com/gogeometry]Antonio Gutierrez[/url].[br][br]The [b]LARGE WHITE POINT[/b] is moveable. [br][br][b][color=#ff00ff]How would you describe the context of this problem in your own words? [br][br]How can we formally prove what is dynamically illustrated here? [/color][/b]