In Euclidean geometry, the problems and shapes deal with flat surfaces. But the world isn't flat. So we're going to take a look at non-Euclidean geometry, or the geometry that deals with 3D ...

Non-Euclidean geometry doesn't operate that way. A triangle inscribed on the surface of a sphere — a spherical geometric space — has more than 180 degrees in its internal angles, and one drawn ...

THIS work will be found really valuable by all students of geometry, especially by those who know little or nothing of the non-Euclidean theories. First of all we have a discussion of the ...

On the other hand, Gauss was interested in the theory of parallels from at least 1799; and some time between 1808 and 1816 he arrived at the belief that non-Euclidean geometry was possibly true ...

Following the rules. Most geometry used in everyday life is the geometry of flat spaces, or Euclidean geometry, so called because the Greek mathematician Euclid wrote down many of its principles ...