1. 3.4 Parallel and Perpendicular Lines 1

2. Objectives  Understand the difference between parallel and perpendicular lines  Use the properties of parallel and perpendicular lines to solve for angle measurements

3. Parallel and Perpendicular Lines  Parallel lines  Coplanar lines that do not intersect  Perpendicular lines  Coplanar lines that intersect at 90 o

4. Transitive Property of Parallel Lines  Theorem 3.7 – if two lines are parallel to the same line, then they are parallel to each other If a || b and b || c then a || c

5. Theorem 3.8  Theorem 3.8 – if two lines are perpendicular to the same line, then they are parallel to each other. Notation for Perpendicular

6. Perpendicular Transversal Theorem  Theorem 3.9 – if a line is perpendicular to one of two parallel lines, then it is also perpendicular to the other

7. Take Home Message  Parallel vs Perpendicular  Perpendicular Transversal Theorem