Kepler was a famous astronomer and mathematician from Germany. He developed three laws of planetary motion that explained how the planets orbit the sun. The laws are:
1. the moving stars round sun move in orbits with the Sun at the focus
2. the area law: the time necessary to go through any part of line of a circle of a moving round sun range of experience is in relation to the area of the sector between the middle of body
3. the harmony law: there is a certain errorless relation between the squares of the planets taking place at regular times and the forms with 6 equal sides of the distance to the center of their orbits.
The first two laws were established in 1609 and the third was published in 1619.
