Geometry Fundamentals: Undefined and Defined Terms

A set of vocabulary flashcards covering the basic undefined terms, defined terms, and notation rules of geometry based on the lecture transcript.

Undefined Terms

The foundational geometric concepts of point, line, and plane, which are accepted without formal definitions.

Point

Specifies an exact location with no size, no dimension, and no length, width, or height; named using a capital letter.

Line

A straight path with no thickness or width that consists of infinitely many points and extends endlessly in opposite directions.

Plane

A flat surface containing points and lines that extends infinitely in all directions; it can be named by a capital letter or three non-collinear points.

Collinear Points

Points that lie on the same line.

Coplanar Points

Points that lie on the same plane.

Ray

A part of a line that consists of one endpoint and extends infinitely in one direction.

Line Segment

A part of a line bounded by two distinct endpoints that has a fixed length and cannot extend.

Angle

A geometric figure formed by two rays sharing a common endpoint.

Vertex

The common endpoint where two rays meet to form an angle; it must be the middle letter when naming the angle.

Sides of an Angle

The two rays that form the angle.

Ray Naming Convention

The rule stating that the endpoint must be written first when naming a ray.