Kepler's second law

Statement of Kepler's second law, or the "Law of areas": the radius-vectors connecting planets to the Sun sweep out equal areas in equal times. The radius-vector is an imaginary straight line connecting the Sun, which is located at one of the foci of the ellipse, to the planet lying on the ellipse.

This second law makes it possible to state that a planet will move faster in its orbit at the perihelion than at the aphelion.