| A | B |
| Converse | The result of when you switch the hypothesis and the conclusion from the original conditional. |
| Segment | The part of a line containing two end points and all points between them. |
| Conjecture | An educated guess. |
| Parallel lines | Lines that lie in the same plane but do not intersect. |
| Collinear | Points that are on the same line. |
| Deductive reasoning | Reasoning based on fact. |
| Bisector | Divides an angle into 2 congruent angles. |
| Complementary angles | Two angles whose sum is 90o. |
| Acute angle | An angle that has a measure less than 90o. |
| Midpoint | The point that separates a segment into congruent parts. |
| Supplementary angles | Two angles whose sum is 180o. |
| Perpendicular lines | Lines that intersect to form right angles. |