Fait mathématique: 1945 is the number of triangles of any size contained in the triangle of side 19 on a triangular grid.
Culture générale: 1945 is an uninteresting number.
Date historique: April 28th is the day in 1947 that Thor Heyerdahl and five crew mates set out from Peru on the Kon-Tiki to prove that Peruvian natives could have settled Polynesia.