# Geometry Theorems

## 21 terms · Geometry Theorems as numbered in McDougal Little textbook.

### Right Angles

1.) If two angles are right angles, then they are congruent. pg 24

### Straight Angles

2.) If two angles are straight angles, then they are congruent. pg 24

### Conditional Statement

3.) If a conditional statement is true, then the contrapositive of the statement is also true. (If p, then q <=> If ~q, then ~p.) pg 46

### Supplementary Angle: Same

4.) If angles are supplementary to the same angle, then they are congruent. pg 76

### Supplementary: Congruent

5.) If angles are supplementary to congruent angles, then they are congruent. pg 77

### Complementary: Same

6.) If angles are complementary to the same angle, then they are congruent. pg77

### Complementary: Congruent

7.) If angles are complementary to congruent angles, then they are congruent. pg 77

8.) If a segment is added to two congruent segments, the sums are congruent. (Addition Property) pg 82

9.) If an angle is added to two congruent angles, the sums are congruent. (Addition Property) pg 83

10.) If congruent segments are added to congruent segments, the sums are congruent. (Addition Property) pg 83

11.) If congruent angles are added to congruent angles, the sums are congruent. (Addition Property)

### Subtract

12.) If a segment (or angle) is subtracted from congruent segments (or angles), the differences are congruent. (Subtraction Property)

### Subtract: Congruent

13.) If congruent segments (or angles) are subtracted from congruent segments (or angles), the differences are congruent. (Subtraction Property)

### Multiples

14.) If segments (or angles) are congruent, their like multiples are congruent. (Multiplication Property)

### Division

15.) If segments (or angles) are congruent, their like divisions are congruent. (Division Property)

### Transitive: Same

16.) If angles (or segments) are congruent to the same angle (or segment), they are congruent to each other. (Transitive Property)

### Transitive: Congruent

17.) If angles (or segments) are congruent to congruent angles (or segments), they are congruent to each other. (Transitive Property)

### Vertical Angles

18.) Vertical angles are congruent.