| A | B |
|---|
| ray | a part of a line having only one endpoint |
| point | an exact location in space |
| line | a collection of points extending endlessly along a path |
| acute angle | 60 degrees, less than 90 degrees |
| obtuse angle | 150 degrees, greater than 90 degrees but less than 180 |
| right angle | measures exactly 90 degrees |
| straight angle | measures exactly 180 degrees |
| angle | two rays having a common endpoint called a vertex |
| plane | an endless flat surface determined by 3 points not on a line |
| line segment | a part of a line having 2 endpoints |
| parallel lines | lines in the same plane that never intersect |
| perpendicular lines | lines that intersect to form right angles |
