The book “De Divina Proportione” (The Divine Proportion) was written in about 1497 by Luca Pacioli, illustrated by Leonardo Da Vinci and first published in 1509. The book contains dozens of beautiful illustrations of three-dimensional geometric solids and templates for script letters in calligraphy.

In the book, Pacioli writes of mathematical and artistic proportion, especially the mathematics of the golden ratio and its application in art and architecture.

The original manuscript can be viewed online at 

https://issuu.com/s.c.williams-library/docs/de_divina_proportione

(Credit: https://www.goldennumber.net/leonardo-da-vinci-golden-ratio-art/)

 

Finally, if you want to know how many golden ratios might appear in a beautiful face, you can watch the video below.