Creation of this applet was inspired by a [url=https://twitter.com/gogeometry/status/959527408830484480]tweet[/url] from [url=https://twitter.com/gogeometry]Antonio Gutierrez[/url]. [br][br]You can move the [b]LARGE VERTICES[/b] of the [b][color=#bf9000]RIGHT TRIANGLE[/color][/b] anywhere you'd like at any time. [br][br][b][color=#ff00ff]What is the measure of the pink angle?[/color][/b][br]What is the measure of the angle with [b][color=#38761d]green vertex[/color][/b] that has sides that pass through the [b][color=#38761d]other 2 green points[/color][/b]? [br][br][b][color=#38761d]How can we formally prove this to be true?[/color][br] [/b]