The Animation

Here’s a beguilingly simple way to do it––move every point to its image in a straight line. What we do is move the corners at constant speed and then the lines follow along.

Notice the interesting three dimensional effect. Even though the individual points all travel in straight lines, the whole shape appears to rotate.

And there’s a point at which the image lies in a straight line–– the lines are all on top of each other. Is that the half-way point? Can you establish that?