Animated horizontal chord of circle
Hello! I'd like to create and export an animation of a chord in a circle that starts as the full horizontal diameter of a circle with radius 2 (so, a length 4 horizontal chord), and ends below itself as a horizontal chord with length 2. It seems that the best way to do this would be to attach two points to the circle at either end of the horizontal equator, and animate them both, the leftmost one counterclockwise, and the rightmost one clockwise.
I only know how to animate single points on a circle, but not two simultaneously, and I also don't know how to make the points stop moving once the chord length has decreased from 4 to 2.
What is the best way to do this?