Drag with the mouse. Left and right arrow keys to rotate, up and down arrow keys to scale. Above 10 iterations, it becomes pretty laggy. Still, pretty. Above 12 lags out my pretty good machine. If you press "0" you can manually type in a huge number. But beware, it will not automatically redraw, or respond to keys or mouse. Press "space" to redraw at large scale. Move and rotate at a smaller iteration, then amp up the iteration again. Here's a fun secret: you can press "i" and "o" to change the right angle beyond its normal limits.
Koch Snowflake now! I don't know why it's missing a single section.