Columbia University Library MS Or 282,
Persian translation by Qotb al-Din Chirazi of
Nasīr al-Dīn al-Tūsī’s edition of Euclid’s Elements,
dated beginning of Shaʻbān in 780 A.H.
(December 1378 CE)
,


fol 21, figures IV.4 et 5 en bas de page



α               Σ                 ©