| A | B |
|---|
| ray | Extends indefinitely in ONE direction, had exactly ONE endpoint. |
| angle | Figure formed by TWO NONCOLLINEAR rays with a common endpoint. |
| vertical angles | 2 non-adjactent angles formed by intersecting lines. |
| perpendicular lines | 2 lines that intersect to for a right angle. |
| acute angle | Ange with a measure of less than 90 degrees. |
| obtuse angle | Ange with a measure of more than 90 degrees AND less than 180 degrees. |
| right angle | Ange with a measure of exactly 90 degrees. |
| straight angle | Ange with a measure of exactly 180 degrees. |
| vertex | The common endpoint of the 2 rays forming an angle. |
| opposite rays | 2 rays whose common endpoint is between the other points on each ray. |
| measure of an angle | The number of degrees between the sides of the angle. |
| Angle Addition Postulate | The sum of the parts equals the whole. |
| congruent | having the same measure. |
| vertical angles | 2 angles directly across the vertex from each other. |
| straight angle | An angle formed by 2 opposite rays. |
| ray AB |  |
| Angle ABC |  |
| Measure of angle ABC |  |
