Hans Holbein the Younger’s masterpiece ‘The Ambassadors’ is full of interesting mathematical details. The polyhedron on the top shelf is a traveller’s sundial. The partially opened book on the lower shelf is a book of arithmetic by Peter Apian printed in 1527. It was on the title page of this book that Pascal’s triangle was first printed in Europe.
 

The skull in the foreground at the bottom of ‘The Ambassadors’ is an anamorphic image. It has been painted so that the perspective is only correct when it is viewed from a very acute angle.