A compound-complex sentence combines the compound and the complex sentence. The compound part means that it has two or more complete sentences. The complex part means that it has at least one incomplete sentence.
Archimedes' principle. Archimedes' principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces and acts in the upward direction at the center of mass of the displaced fluid. Archimedes' principle is a law of physics fundamental to fluid mechanics. It was formulated by Archimedes of Syracuse.
Little is known about Archimedes's life. He probably was born in the seaport city of Syracuse, a Greek settlement on the island of Sicily in the Mediterranean Sea. He was the son of an astronomer (someone who studies outer space, such as the stars) named Phidias. He may also have been related to Hieron, King of Syracuse, and his son Gelon. Archimedes studied in the learning capital of Alexandria, Egypt, at the school that had been established by the Greek mathematician Euclid (third century B.C.E. ). He later returned to live in his native city of Syracuse.