List of Kepler's laws of planetary motion

This post is a list of Kepler's laws of planetary motion. Johannes Kepler published the first 2 laws in 1609 and the 3rd law in 1619. There are 3 laws listed below. Source: Wikipedia

1. "The orbit of a planet is an ellipse with the Sun at one of the two foci."
2. "A line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time."
3. "The square of a planet’s orbital period is proportional [at Kepler's constant] to the cube of the length of the semi-major axis of its orbit."