Types of Triangles

AB is the radius of a circle. The slider changes the radius to a value between 0 and 5. The two red lines are perpendicular to AB, and point D can be moved to any point on the circle.
1. Take some time to play around with the applet. Note any relationships you see in regards to side and angle measures. 2. Regardless of the location of D, what type of triangle would this be? Explain your reasoning. 3. Move D to the left perpendicular line (the one through A). What do you notice? What type of triangle is this? Explain. 4. Move D to the right perpendicular line (the one through C). What happened to the triangle? What type of triangle is this? Explain. 5. Move D until AD is collinear with AB. What happened to the triangle. Why? Explain.