Philippe de La Hire

Philippe de La Hire ( born March 18, 1640 Paris, † April 21, 1718 ) was a French mathematician.

He was trained as an artist and traveled to Italy for four years to improve his artistic skills. He also learned the basics of geometry. He first made himself known by a number of important time work on conics, mechanics, hydrostatics and others and through his with Jean Picard Jean -Baptiste Colbert arrangement published map of France and its executed with respect to a water supply of Versailles leveling. He proved to be the first that the hypotrochoids of Cardano circles are all ellipses and developed a trammel.

In 1678 he was elected to the Académie des sciences.

1708 he calculated the circumference of the cardioid.