| A | B |
|---|
| Acute Angle | An angle measuring more than 0 but less than 90 |
| Angle Bisector | The ray that divides an angle into two congruent angles |
| Biconditional Statement | p if and only if q |
| Conclusion | The "then" part of a conditional statement |
| Complementary Angles | Two angles whose sum measures 90 degrees |
| Converse | Statement formed by interchanging the hypothesis and conclusion of the conditional |
| Counterexample | Proves a conditional statement false |
| Collinear | Points, segments, or rays that lie on the same line |
| Contrapositive | Statement formed by negating both the hypothesis and conclusion of the converse |
| Coplanar | Points, segments, or rays that are in the same plane |
| Conditional statement | Another name for an "if-then" statement |
| Hypothesis | The "if" part of the conditional statement |
| Inverse | Formed by negating both the hypothesis and and conclusion of a conditional statement |
| Linear Pair | Two adjacent angles whose noncommon sides are opposite rays |
| Midpoint | The point that divides the segment into two congruent segments |
| Obtuse | An angle measuring more than 90 but less than 180 |
| Oblique | Two lines that intersect but not at a 90 degree angle |
| Perpendicular | Two lines which intersect to form a right angle |
| Parallel lines | Two coplanar lines which never intersect |
| Parallel planes | Two planes that do not intersect |
| Reflexive property | An object is congruent to itself |
| Skew | Lines that are not coplanar |
| Slope | The change in y divided by the change in x |
| Supplementary angles | Two angles whose sum measures 180 |
| Segment bisector | A segment, ray, line ot plane that intersects a segment at its midpoint |
| Straight angle | An angle whose measure is 180 |
| Theorem | A statement that must be proved to be true |
| Vertex | The common point of the two rays that form an angle |
| Vertical angles | Two angles whose sides form two pairs of opposite rays |
