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.
Luca Pacioli is widely considered the "Father of Accounting". Also, his treatise touches on a wide range of related topics from accounting ethics to cost accounting. Remarkably, in the solution for one problem he presented in the book he used an approximation of 100*log 2, more than 100 years before Napier and Briggs.