# 3. Exercises¶

1. Here is another interesting L-System called a Hilbert curve. Use 90 degrees:

L
L -> +RF-LFL-FR+
R -> -LF+RFR+FL-

2. Here is a dragon curve. Use 90 degrees.:

FX
X -> X+YF+
Y -> -FX-Y

3. Here is something called an arrowhead curve. Use 60 degrees.:

YF
X -> YF+XF+Y
Y -> XF-YF-X

4. Try the Peano-Gosper curve. Use 60 degrees.:

FX
X -> X+YF++YF-FX--FXFX-YF+
Y -> -FX+YFYF++YF+FX--FX-Y

5. The Sierpinski Triangle. Use 60 degrees.:

FXF--FF--FF
F -> FF
X -> --FXF++FXF++FXF--

6. Here are the rules for an L-system that creates something that resembles a common garden herb. Implement the following rules and try it. Use an angle of 25.7 degrees.

H
H --> HFX[+H][-H]
X --> X[-FFF][+FFF]FX

7. Here is another L-System. Use an Angle of 25.

F
F --> F[-F]F[+F]F