Spirolaterals

Imagine you have a little robot that holds a pencil. Set it down on a sheet of paper and give it these instructions:

1.Move forward 3 units and turn right.
2.Move forward 1 unit and turn right.
3.Move forward 2 units and turn left.
4.Move forward 1 unit and turn left.
5.Move forward 2 units and turn right.
6.Repeat.

If the robot makes its turns at 90° angles, it will produce this figure:








But, remarkably, if it turns at 120° it will draw this:








That's pretty crazy!!

Via