Portrait of Luca Pacioli, father of accounting, painted by Jacopo de' Barbari, 1495, (Museo di Capodimonte).
De Divina Proportione - a book on mathematics written by Luca Pacioli and illustrated by Leonardo da Vinci, composed around 1498 in Milan and first printed in 1509
De Divina Proportione is a book by Luca Pacioli illustrated by Leonardo da Vinci
Jacopo de Barbari. "Portrait of the mathematician Luca Pacioli" (1495)
A, Illustration from 'Divina Proportione' by Luca Pacioli (C.1445-1517), Originally Pub. Venice,… Giclee Print by Leonardo da Vinci at Art.co.uk
La S para la Divina Proporción: Luca Paccioli
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.
Portrait of Luca Pacioli