April 15 is the birthday of the great Renaissance painter and inventor Leonardo da Vinci. Da Vinci was born on in 1452. Among his many accomplishments, da Vinci is known for transforming the ideas of Roman architect Vitruvius into one of the world's most famous drawings, The Vitruvian Man. The archetypal man da Vinci drew became a symbol for concepts of "spiritual geometry" and classical theories of proportion and design.

• Spiritual Geometry
• Da Vinci's Vitruvian Man

^{Image: Jupiterimages Corporation}