| A | B |
|---|
| acute | An angle with a measure between O and 90 degrees. |
| obtuse | An angle with a measure greater than 90 degrees and less than 180 degrees. |
| right | An angle with a measure of 90 degrees. |
| reflex | An angle with a measure greater than 180 degrees and less than 360 degrees. |
| straight | An angle with a measure of 180 degrees. |
| complementary | Two angles whose measures have a sum of 90 degrees. |
| supplementary | Two angles whose measures have a sum of 180 degrees. |
| vertical | Angles formed opposite from each other when two line intersect (they are always congruent). |
| parallel lines | Lines in the same plane that never intersect. |
| perpendicular lines | Lines that intersect to form right anlges. |
| intersecting lines | Lines that lie in the same plane and have exactly one point in common. |
