My version of an animation that has been created and recreated many times on the internet. I first saw it as [url=https://www.youtube.com/watch?v=pNe6fsaCVtI]"Crazy Circle Illusion" on Brusspup's YouTube channel[/url].[br][br]Press [color=#999999]Play[/color]. What do you observe?[br]You're likely to say something like, "A circle rolling inside a larger circle."[br]But how else could you interpret what you see? Maybe a polygon rolling inside a circle? Or if it's a polygon, must the points represent the vertices of the polygon? Could they be lateral midpoints or some other points of the polygon? Any other interpretations? [br][br]What else do you notice about the geometry in this animation?[color=#999999][br][/color][br]Check the [color=#6fa8dc]Highlight one point box[/color], and then make on observation about that point.[br][br]Check the [color=#999999]Show additional geometry[/color] box to see if it affirms your observation.