🌐EnglishEnglishDeutschEspañolFrançaisItalianoNederlandsPortuguêsSvenskaTiếng ViệtTürkçeРусскийالعربية中文日本語EntityQ748233· pop 16· linked from 54 articlesSylvester–Gallai theoremtheorem that every finite set of points in the plane, not all collinear, has a line through exactly two pointsConnectionsJames Joseph SylvesterEntityEuler characteristicEntityCategoriesEuclidean plane geometryMatroid theoryTheorems in discrete geometry