# Parallel Lines and Angles

- Author:
- Katia Clouse

- 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 _______________________________.