Robuta

https://www.open.edu/openlearn/mod/oucontent/view.php?id=138814&extra=longdesc_id49 (Disgrifiad) Ffigwr 15: Normau gweithio newydd | OpenLearn disgrifiad 15 gweithio newydd openlearn https://www.open.edu/openlearn/mod/oucontent/view.php?id=94670&extra=longdesc_id17 (Disgrifiad) Ffigur 11 Llinellau cymesuredd lluosog | OpenLearn disgrifiad 11 openlearn