1. Parallel Lines Properties of Angles Formed by Parallel Lines and a Transversal

2. Parallel lines (Definition) A line that intersects both parallel lines is called a transversal. Which is the transversal in the diagram above?

3. Parallel lines

4. Corresponding Angles

5. Alternate Angles (they alternate…) Alternate Interior: inside the parallel lines, on either side of the transversal Alternate Exterior: outside the parallel lines, on either side of the transversal

6. Same Side Interior These angles are on the same side of the transversal and inside the parallel lines.