Geometry is the branch of mathematics that deals with measurements and properties of points, lines, and angles. Geometry is one of the oldest branches of mathematics, used by the Egyptians and Babylonians as early as 2000 B.C. The ancient Egyptians and Babylonians had a practical knowledge of many geometric ideas, which they applied to surveying and construction projects; the first meaning of the word "geometry," which is of Greek origin, was "measurement of the earth." Early tablets have shown that the Egyptians and Babylonians formed reasonable estimates of the value of pi (), and that the Babylonians were aware of the Pythagorean theorem, which gives a relationship between the lengths of the sides of a right triangle. The Egyptians and Babylonians discovered geometric ideas largely through experimental means--from examining the measurements of physical objects.

Geometry came into its own in the time of the Greeks, who developed the notion...