GoGeometry Action 127!
Creation of this applet was inspired by a problem posted by Antonio Gutierrez (GoGeometry).
You can move the 2 LARGE VERTICES of the triangle anywhere you'd like at any time.
You can alter the size of the angle with BLUE VERTEX with the BLUE SLIDER.
You can alter the size of the angle with YELLOW VERTEX using the YELLOW SLIDER.
How would you describe the phenomenon you see in your own words?
How can we formally prove this phenomenon to be true regardless of the locations of the orange point, the purple point, and the green point?