This is a small script from my school days, which draws a Sierpiński triangle using random numbers.
This is a well known example of a chaos game. Using turtle, it produces a Sierpiński triangle, which is a nice looking fractal.
This script (without some enhancements) was created at a course at the "Mathematische Schülergesellschaft Leonhard Euler" some years ago.
To get it to work, I had to do some searching. These links may help you.