| A | B |
|---|
| Linear Pair Theorem | If two angles form a linear pair, then they are supplementary |
| Congruent Supplements Theorem | If two angles are supplementary to the same angle (or to two congruent angles), then the two angles are congruent |
| Right Angle Congruence Theorem | All right angles are congruent |
| Congruent Complements Theorem | If two angles are complementary to the same angle (or to two congruent angles), then the two angles are congruent |
| Common Segment Theorem | If AB = CD, then AC = BD |
| Vertical Angles Theorems | Vertical angles are congruent |
| Complementary Angles | Angles that add up to 90 degrees |
| Supplementary Angles | Angles that add up to 180 degrees |
| Midpoint of a line | A point that divides a line evenly, making the two lines congruent |
| Angle bisector | A ray the divides an angle evenly, making the two angles congruent |
