Wanner, Gerhard F. Commandino, de centro gravitatis solidorum, 1565. (English) Zbl 1431.51001 Elem. Math. 73, No. 4, 179-181 (2018). In a tetrahedron, the barycenter (centrum gravitatis), i.e. the point where the medians meet, divides these medians in proportion 3:1. This result which is attributed to the 16th-century mathematician Federico Commandino is given a stunning short proof by the author by applying Menelaus’ theorem. Reviewer: Martin Lukarevski (Skopje) MSC: 51-03 History of geometry 01A40 History of mathematics in the 15th and 16th centuries, Renaissance 51M04 Elementary problems in Euclidean geometries Keywords:tetrahedron; barycenter; medians; centrum gravitatis Biographic References: Commandino, Federico PDFBibTeX XMLCite \textit{G. Wanner}, Elem. Math. 73, No. 4, 179--181 (2018; Zbl 1431.51001) Full Text: DOI References: [1] Federici Commandini Urbinatis, Liber de centro gravitatis solidorum, Bononiæ, Ex Officina Alexandri Benacii. MDLXV (Bologna 1565). [2] J.P. Hogendijk, The lost geometrical parts of the Istikm¯al of Y¯usuf al-Mu’taman ibn H¯ud(11th century) in the redaction of Ibn Sart¯aq(14th century): an analytical table of contents, Arch. Internat. Hist. Sci. 53 (2003) 19-34. · Zbl 1166.01007 [3] A. Ostermann, G. Wanner, Geometry by its history, Springer, 2012. · Zbl 1288.51001 This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.