The next function is to outline shapes. Do it as followed:

outline(?,?,?);

The three question marks are for coloring an outline. The next code cancels all outline written so you don't have to delete them one by one. Here it is:

outlineoff();

The blank means nothing goes in the parentheses. That exact line will do the function. The next one will let you set the thickness of the lines:

outlinethickness(?);

The question mark is the thickness. Well, that's it! The rest of the code to learn is on: khanacademy.org

The next chapter is Pro Tips and fun facts on DS. Enjoy!