Euclidean theorem may refer to: Any theorem in Euclidean geometry Any theorem in Euclid's Elements, and in particular: Euclid's theorem that there are infinitely many prime numbers Euclid's lemma, also called Euclid's first theorem, on the prime factors of products The Euclid–Euler theorem characterizing the even perfect numbers Geometric mean theorem about right triangle altitude
See also Euclidean (disambiguation) Euclid (disambiguation)