Book on the Measurement of Plane and Spherical Figures

The Book on the Measurement of Plane and Spherical Figures (Arabic: كتاب معرفة مساحة الأشكال البسيطة والكريّة, Kitāb maʿrifah masāḥat al-ashkāl al-basīṭah wa-al-kuriyyah)[note 1] was the most important of the works produced by the Banū Mūsā (three 9th century Persian brothers who worked in Baghdad).

[2] A Latin translation by the 12th century Italian astrologer Gerard of Cremona was made, entitled Liber trium fratrum de geometria and Verba filiorum Moysi filii Sekir.

The original work in Arabic was edited by the Persian polymath Naṣīr al-Dīn al-Ṭūsī in the 13th century.

[5] It deals with the geometrical concepts of area and volume, angle trisection, construction, and conic sections.

[7] The book was re-published in Latin with an English translation by the American historian Marshall Clagett, who has also summarized how the work influenced mathematicians during the Middle Ages.