EntityQ4515035· pop 8· linked from 32 articlesHilbert's fourth problemSign in to saveone of twenty-three, asking to construct all metric spaces where lines resemble those on a sphereWikidata factsInstance ofmathematical problemPart ofHilbert's problemsNamed afterDavid Hilbertvia Wikidata · CC0ConnectionsAmerican Mathematical SocietyEntitymathematicsEntityCategoriesFoundations of geometryGeometry problemsHilbert's problems