Just follow the line! Click and drag to draw (or use the spacebar). Carefully trace the line to draw a penrose triangle. Press 'h' when you're done to hide the guide. Press 's' to show the guide again. Press 'n' to see the other guide. Press 'c' to clear.
Thanks to the original project by @scratchisthebest !!! This is a remix so I didn't figure out how do do this! Changes: Color of pen Color of circles you use to draw New guide