non-Euclidean geometry

 non-Euclidean geometry on Wikipedia

• noneuclidean geometry US

non-Euclidean geometry (countable and uncountable, plural non-Euclidean geometries)

1. (geometry) Any system of geometry not based on the set of axioms of Euclidean geometry, which is based on the three-dimensional space of common experience.

• Euclidean geometry

• hyperbolic geometry
• elliptical geometry
• spherical geometry

• absolute geometry
• parallel postulate