# Parallel Lines and Angles

Topic:
Angles
This GeoGebra is intended to help you identify the special angles formed by parallel lines and a transversal. In addition, you should be able to make some conjectures about the relationships between these special angle pairs.
In the diagram, consider the parallel lines a river, and the brown transversal crossing it a bridge. The Special Angle Pairs formed by parallel lines and a transversal are always on opposite river banks. Corresponding Angles are on the same side of the bridge, one inside the river and one outside. Angles _____ and _____ are corresponding angles. Alternate Interior Angles are on opposite sides of the bridge, inside the river. Angles _____ and ____ are alternate interior angles. Alternate Exterior Angles are on opposite sides of the bridge, outside the river. Angles _____ and _____ are alternate exterior angles. Same-Side Interior Angles are on the same side of the bridge, inside the river. Angles _____ and _____ are same-side interior angles. As you manipulate these angles by moving Points A and B, you can make conjectures about the relationships between these angles. Corresponding Angles are __________________________. Alternate Interior Angles are ___________________________. Alternate Exterior Angles are ______________________________. Same-Side Interior Angles are _______________________________.