The Fundamentals (Dimension 0 & 1)
Start with the language geometry is built on: points, lines, segments, rays, midpoint ideas, intersections, and the basic postulates used to describe measurement.
11 concepts in this topic
This category gives you the vocabulary that later topics rely on. It is the right place to learn how a figure is named, what a label really means, and how small diagram details change the geometry.
Point
The basic location in space.
Line
A line has no endpoints and extends infinitely in both directions.
Line Segment
A line segment has two endpoints and a finite length.
Ray
A ray has one endpoint and extends infinitely in one direction.
Opposite Rays
Opposite rays share an endpoint and form a straight line.
Midpoint
The midpoint divides a segment into two equal parts.
Segment Bisector
A segment bisector passes through a segment's midpoint.
Collinear Points
Collinear points lie on the same line.
Coplanar Points
Coplanar points lie on the same plane.
Intersection
An intersection is the point or line where figures meet.
Postulates & Axioms
Postulates and axioms are accepted rules such as the ruler postulate and segment addition.