1. Construct the astroid. 

2. Construct the astroid as envelope of lines. 

3. Construct the deltoid this way. 

4. Construct the cardioid as thus: 

5. Construct the nephroid as thus: 

6. Draw this "starshaped" curve: 

7. Construct the deltoid as envelope of lines as thus: 

8. Construct the astroid as envelope of lines as thus: 

9. Construct the ellipse and the hyperbola as envelope of lines.  

