#### Answer

Kepler's three laws of planetary motion are described as follows: :
(1) Law of orbits: All planets move in elliptical orbits haying the Sun as one focus.
(2) Law of areas: A line or radius vector $r(t)$ or a line segment that connects any planet to the sun sweeps out equal areas in equal time of period.
(3) Law of periods: The square of the orbital period of any planet is proportional to the cube of the semi-major axis of its orbit.