Answer:
The Vitruvian man is a man whose body's proportions are perfect. For this to happen, his limbs, when extended, should touch the edge of a circumference drawn around him.
Da Vinci's Vitruvian man is not based on the body propostions described by Roman architect Vitruvius in his work De Architectura. Da Vinci instead, based the proportions on the measurements that he made of real models while working in Milan.
