Geometry: Sets and Points Terminology

These flashcards cover key vocabulary and concepts related to sets, points, lines, and planes in geometry.

Set

A collection of elements, which could be numbers, letters, or symbols.

Finite Set

A set that has a countable number of elements.

Infinite Set

A set that has an uncountable number of elements.

Empty Set

A set with no elements, represented as { } or Ø.

Point

A location in space represented by a dot and named by a capital letter; it has no length, width, or thickness.

Line

A set of points that extends endlessly in both directions; requires two points to define.

Plane

A set of points forming a completely flat surface that extends indefinitely in all directions.

Collinear Points

Three or more points that lie on the same line.

Noncollinear Points

Three or more points that do not lie on the same line.

Line Segment

A subset of a line consisting of two endpoints and all points between them.

Midpoint

The point on a line segment that divides the segment into two equal parts.

Congruent Segments

Segments that have equal measure.

Line Bisector

Any line or part of a line that intersects a line segment at its midpoint.