The Vitruvian Man is a famous drawing of man's proportions. It was created by Leonardo da Vinci between 1490 and 1492. Based on architectural & mathematical theories put forward by Vitruvius, the Roman Architect.

The Vitruvian man is an ongoing source of debate as to what exactly it means. Some people believe is has hidden symbolism and religious comments and/or representations. Some believe it is Leonardo's way of trying to prove mathematical theories behind the proportions of the human body and it's relationship to the most simple of geometric forms; a circle and the square. Some say it is simply a drawing illustrating a perfect ratio much like the golden mean. Is Leonardo trying to reconcile the opposites of square and circle? or is Leonardo proving a proportional rule for the perfect humans? 

In the Vitruvian man the circle and the square are both equal in surface area. The circle is centered at the man's navel and the square is centered around the man's entire proportion of total height and width.