varying surfaces, whereon a point and som lines are "drawn" to demonstrate euclidian elliptical and hyperbolic geometry To be exact, the hyperbolic surface
org/publicdomain/mark/1.0/PDMCreative Commons Public Domain Mark 1.0falsefalse English Illustration of non-euclidiangeometry, by Roberto Bonola, Zanichelli 1905
DescriptionGeometriflader.jpg English: Special version of File:Euclidian_and_non_euclidian_geometry.png for "Article of the Day" on the main page of the Danish