| A | B |
|---|
| point | exact location in space |
| line | infinite number of points that are aligned with each other |
| line segment | part of a line that starts and stops at a specific point |
| ray | part of a line that has one endpoint and goes on in the opposite direction forever |
| intersecting lines | lines that meet at only one point |
| angle | formed by 2 rays and have a common endpoint |
| vertex | common endpoint of an angle |
| acute angle | an angle that measures between 0 and 90 degrees |
| obtuse angle | an angle that measures between 90 and 180 degrees |
| right angle | an angle that measures exactly 90 degrees |
| straight angle | an angle that measures exactly 180 degrees |
| adjacent angles | 2 angles with a common vertex and a common side |
| supplementary | 2 angles whose sum is 180 degrees |
| protractor | tool used to measure and to draw angles |
