Portrait of Luca Pacioli, father of accounting, painted by Jacopo de' Barbari, 1495, (Museo di Capodimonte).
Luca Pacioli – Letra S, De Divina Proportione
Polyhedron - Wikipedia
Whilst in Milan, Leonardo became very interested in Mathematics, also. He illustrated one of the first modern math books, done by a friend of his, Luca Pacioli.
Leonardo da Vinci drew the illustrations for Luca Pacioli's 1509 book De Divina Proportione (The Divine Proportion). Drawing of the Duodecedron Abscisus Elevatus Vacuus, consisting of 120 equilateral triangles, from the manuscript of the book.
Topics in 3D: Triangulation Error
La Divine proportion de Luca Pacioli
La A di Luca Pacioli. Lettera A, De divina proportione, Venezia 1509