[AntonioLao]

Desargues’ theorem is a theorem of projective geometry. The complicated proofs have been provided for the 2D Euclidean plane and the 3D Euclidean space. But what could be the 4D Euclidean equivalent of these proofs?

In order to show depth, many of the Renaissance paintings (starting with Leonardo da Vinci’s and Albrecht Durer’s) have been based on points at infinity of projective geometry. And modern architectural projective drawings can’t be done without all these points lying on a single line at infinity.

Projective geometry is a branch of mathematics and was discovered by the Frenchman Jean-Victor Poncelet, when he was a prisoner of war in Russia in 1813.