Processing Help.

/*

Processing has help:

From the IDE Menu Help, Reference.

From code highlight a word,

Menu, Help, Find in Reference. (control-shift-F).

Try it:

• copy and past all this into a new Processing window (^n)

• highlight the word rect, press control-shift-F

• see the description of the 5th parameter "r"

• add a 5th parameter of 5, run, see the result

• Select Menu, Help, Reference

• see "arc()" and click on it.

• Copy the 5 lines of the first example, paste in the sketch window.

• Run (^r)

*/

rect(10, 30, 50, 20);