plane geometry

noun

Mathematics.

1. the geometry of figures whose parts all lie in one plane.

plane geometry

noun

1. the study of the properties of and relationships between plane curves, figures, etc

plane geometry

1. The mathematical study of geometric figures whose parts lie in the same plane, such as polygons, circles, and lines.

plane geometry

1. The study of two-dimensional figures (figures that are confined to a plane).

Plane geometry is one of the oldest branches of mathematics.

The Greek mathematician Euclid was the first to study plane geometry carefully. His book Elements was the standard plane geometry textbook for centuries.

Word History and Origins

Origin of plane geometry¹

First recorded in 1740–50