Columbia University Library MS Or 49, Kitāb Uṣūl al-handasah wa-al-ḥisāb, كتاب اصول الهندسة والحساب, arabic translation of Euclid's Elements by Nasir ad Din at Tusi copied in the mid- to late-19th century, fol 160, figure XIII.17

Columbia University Library MS Or 49,
Kitāb Uṣūl al-handasah wa-al-ḥisāb,
كتاب اصول الهندسة والحساب,
arabic translation of Euclid's Elements by Nasir ad Din at Tusi
copied in the mid- to late-19th century

fol 160, figure XIII.17 ratée et corrigée

α Σ ©