Curated OER
Geometry In Space
How can we identify shapes in the Universe? High schoolers will compare and contrast elliptic and hyperbolic geometry. They will also explore one possible way to measure the curvature of the Universe, namely, by measuring the sum of the...
Wolfram Research
Wolfram Mathworld: Elliptic Geometry
MathWorld offers a brief definition of elliptic geometry and including a brief discussion of its relationship to Euclidean geometry, with links to other related definitions.
Math Words
Math words.com: Elliptic Geometry
The basic definition for what elliptic geometry is is found here.
Wikimedia
Wikipedia: Elliptic Geometry
This encyclopedia article contains a basic description of what elliptic geometry is.