Behind the Scenes: Inscribed Angle Corollary (1)

In this session, we'll discuss how to use ONLY 1 SLIDER to create a simpler version of this applet: What theorem is dynamically being illustrated here? Feel free to move any of the LARGE POINTS anywhere you'd like!
Let's now examine this applet with a little more details shown: Questions to consider: 1) What happens as the slider moves from a = 0 to a = 1? 2) What happens as the slider moves from a = 1 to a = 2?