Kepler’s second law
The Law of Areas: A line that connects a planet to the sun sweeps out equal areas in equal times.
In other words we can explain this as:
Sometimes referred to as the law of equal areas – describes the speed at which any given planet will move while orbiting the sun. The speed at which any planet moves through space is constantly changing. A planet moves fastest when it is closest to the sun and slowest when it is furthest from the sun.