🌐EnglishEnglishDeutschEspañolFrançaisItalianoNederlandsPortuguêsРусскийالعربيةفارسی한국어中文日本語EntityQ676413· pop 16· linked from 12 articlesDandelin spheresmathematical conceptConnectionsconeEntityconic sectionEntityCategoriesConic sectionsEuclidean solid geometrySpheres