Drag the three black points to change the vertices of the triangle. Press the green flag to start again. Adjust the pen size using the slider. Turbo mode helps, but it is not needed.
This project works by starting at the first point, then by moving halfway to a random one of the three points from where it is. Due to the geometry of this process, it creates the Sierpienski triangle very easily with only one script of about 15-20 blocks using only points (not drawing lines).