Q:

# What are the three basic types of geometry?

A:

There are three basic types of geometry: Euclidean, hyperbolic and elliptical. Although there are additional varieties of geometry, they are all based on combinations of these three basic types. Euclidean geometry is the original form, dating back to 300 BC, and it is the result of the work of the Greek Alexandrian mathematician Euclid, who developed the five postulates, or axioms, upon which his geometric theorems are built.

## Keep Learning

Euclid's fifth postulate, known as the parallel postulate, went without an accompanying proof for thousands of years. The parallel postulate assumes that a straight line crossing through two other straight lines and forming two same-side interior angles of less than 90 degrees determines that those two lines, if extended far enough, will eventually meet on the side of the interior angles. This assumption, however, did not take into account the idea of curved space, which was first conceptualized by Albert Einstein in his 1915 General Theory of Relativity.

The idea of space existing with either a positive or a negative curvature introduced the idea of non-Euclidean geometry, in which the parallel postulate would not always hold true. In curved space, it cannot be assured that the two lines in question will ever meet, regardless of how far they might be extended. The geometry based on space with a negative curvature became known as hyperbolic geometry. Elliptical geometry refers to the type of geometry based on space with a positive curvature.

Sources:

## Related Questions

• A:

Spherical geometry is the branch of mathematics that deals with figures placed on the surface of a sphere. It can also be defined as a three-dimensional view of more traditional planar geometry; although, there are numerous differences between the planar and spherical subsets of geometrical study. Some of the basic tenets of planar geometry don't carry over to spherical geometry because it deals with different mathematical concepts.

Filed Under:
• A:

In Euclidean geometry, the fourth dimension refers to a space with four dimensions, in contrast to a two-dimensional xy-plane and a three-dimensional xyz-plane. While two-dimensional spaces contain two vectors and three-dimensional space contains three vectors, every point in a space in the fourth dimension has four vectors.

Filed Under:
• A:

A geometry tutorial may cover the basic concepts used in planar geometry or cover a specific aspect of geometry more extensively. A tutorial often includes sample problems, lists key concepts and explains the application of different theorems.