Match the word with its definition. Part A1 . Kepler's 1st Law of Planetary Motion 2 . Ptolemaic system 3 . geocentric system 4 . heliocentric system 5 . Copernican system Part Ba. a geocentric system b. the system of planets in circular orbits around the sun. c. planets orbit the sun in elliptical orbits with the sun at one focus.d. the system of the planets and sun in orbit around the earth. e. a heliocentric system