🌐EnglishEnglishDeutschEspañolFrançaisItalianoNederlandsPortuguêsРусскийالعربية한국어中文日本語EntityQ652123· pop 8· linked from 41 articlestriangle groupGroup realized geometrically by reflections across the sides of a triangleAvailable in 8 languagesEspañolFrançaisDeutschРусскийItalianoNederlands한국어via Wikidata sitelinks · CC0Connectionspoint reflectionEntitymodular groupEntityCategoriesCoxeter groupsEuclidean geometryFinite groupsGeometric group theoryHyperbolic geometryPolyhedraProperties of groupsSpherical trigonometryTessellation