Kepler's Second Law8.4 -Understand Kepler's laws of planetary motion
Law #2. The Sun-planet line sweeps out equal areas in equal times.
Planets move faster when they are nearer the Sun (perihelion) and slower when they are further away (aphelion).
If you imagine a line connecting the Sun to the planet, this line sweeps out equal areas in equal times. If you look at the image on the right you will see that the time it takes for the planet to orbit A is the same time for the planet to orbit B.