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Kepler's first law stated that the orbit of a planet regarding the Sun was an ellipse, having the Sun’s center of mass as the focus.
Kepler's second law stated that a line joining a planet with the Sun sweeps out equal areas in equal intervals of time.
Kepler's third law stated that the mean distance cubed over the period squared was the same for each planet. Therefore (r³A/T²A) = (r³B/T²B) [where r is the distance from the sun to the planet and T is the amount of time for the planet to make one orbit around the sun].