| A | B |
|---|
| ray | A part of a line that starts at an endpoint and goes on forever in one direction. |
| angle | a figure formed by to rays with a common endpoint, called a vertex. |
| vertex | the common endpoint of two rays that form an angle. |
| degree | a unit of measurement that is 1/360 of a complete turn. |
| right angle | an angle that has a measure of 90 degrees. |
| straight angle | an angle that has a measure of 180 degrees. |
| acute angle | an angle that has a measure that is greater than 0 degrees, but less than 90 degrees. |
| obtuse angle | an angle that has a measure that is greater than 90 degrees, but less than 180 degrees. |
| supplementary angles | 2 angles who's measure, if added equals exactly exactly 180 degrees. |
| complimentary angles | 2 angles who's measure, if added equals exactly 90 degrees. |
