🌐EnglishEnglishDeutschEspañolFrançaisItalianoNederlandsPolskiPortuguêsTiếng ViệtTürkçeРусскийالعربيةفارسی한국어中文日本語EntityQ119450· pop 22· linked from 20 articlesBrianchon's theoremtheorem that the three long diagonals of a hexagon that is tangent to a conic section meet in a single pointConnectionsgeometryEntityInternational Standard Book NumberEntityCategoriesAffine geometryConic sectionsEuclidean plane geometryTheorems about polygonsTheorems in projective geometry