|
 segment | the part of a line containing two endpoints and all points between them. |
| ray | the part of the line consisting of one endpoint and all the points of the line on the one side of the endpoint. |
| opposite rays | two collinear rays with the same endpoint. |
| parallel lines | coplanar lines that do not intersect. |
| skew lines | noncoplanar lines that do not intersect. |
| parallel planes | planes that do not intersect. |
| congruent segments | segments with the same length |
| midpoint | the point that divides the segment into 2 congruent segments |
| coordinate | the number value assigned to a point. |