I programmed this on my TI-83 back in the day and spent many hours watching it generate triangles during boring classes. You can generate many other fractals (

I programmed this on my TI-83 back in the day and spent many hours watching it generate triangles during boring classes. You can generate many other fractals (e.g. fern shapes) in a similar way, though the transformations are more complicated than “move halfway to selected point”.