| A | B |
|---|
| point | has no size and can be thought of as a location |
| space | the set of all points |
| line | a series of points that extends in two opposite directions without end |
| plane | a flat surface that extends in all directions without end |
| collinear | points that lie on the same line |
| coplanar | points and lines in the same plane |
| postulate | an accepted statement of fact |
| segment | the part of a line consisting of two endpoints and all points between them |
| ray | the part of a line consisting of one endpoint and the points of the line on one side of the endpoint |
| opposite rays | two collinear rays with the same endpoint that form a line |
| parallel lines | coplanar lines that do not intersect |
| skew lines | lines that do not lie in the same plane and are neither parallel nor intersecting |
