Animated Chords in Geogebra: What do you Notice?

Move point A around the circumference of the circle.  You can also start the animation. What do you notice? What questions do you have? You can also move points B, C, and D.

You can use this page to investigate, or open in Geogebratube here.

Teachers can walk students through the tools that are available at the top of the page. (Teachers new to Geogebra can check back later for some intro to the tools in the above Geogebra Worksheet).