# [Geometry] Chapter 3 Theorems

## 11 terms

### Theorem 3.1 (No specific name)

If two lines intersect to form a linear pair of congruent angles, then the lines are perpendicular

### Theorem 3.2 (No specific name)

If two sides of two adjacent acute angles are perpendicular, then the angles are complementary

### Theorem 3.3 (No specific name)

If two lines are perpendicular, then they intersect to form four right angles

### Alternate Interior Angles

If two parallel lines are cut by a transversal, then the pairs of alternate interior angles are congruent

### Consecutive Interior Angles

If two parallel lines are cut by a transversal, then the pairs of consecutive interior angles are supplementary

### Alternate Exterior Angles

If two parallel lines are cut by a transversal, then the pairs of alternate exterior angles are congruent

### Perpendicular Transversal

If a transversal is perpendicular to one of two parallel lines, then it is perpendicular to the other

### Alternate Interior Angles Converse

If two lines are cut by a transversal so that alternate interior angles are congruent, then the lines are parallel

### Consecutive Interior Angles Converse (Same Side Interior Angles Converse)

If two lines are cut by a transversal so that consecutive interior angles are supplementary, then the lines are parallel

### Theorem 3.11 (No specific name)

If two lines are parallel to the same line, then they are parallel to each other

### Theorem 3.12 (No specific name)

In a plane, if two lines are perpendicular to the same line, then they are parallel to each other