🌐EnglishEnglishFrançaisPortuguêsРусскийفارسیEntityQ28456108· pop 6· linked from 5 articlesLebesgue's universal covering problemunsolved geometry problemAvailable in 6 languagesFrançaisРусскийHungarianUkrainianفارسیvia Wikidata sitelinks · CC0ConnectionsgeometryEntitydiameterEntityCategoriesDiscrete geometryUnsolved problems in geometry