This GeoGebra is intended to help you notice relationships between angles formed by intersecting lines.

When angles formed by intersecting lines are across from each other, we call them vertical angles.
An example of vertical angles in this diagram are Angle _____ and Angle _____.
As you manipulate the intersecting lines by moving Points A and C, what observations do you make about vertical angles?
When angles formed by intersecting lines are sharing a common side, they are a linear pair.
An example of a linear pair of angles in this diagram are Angle _____ and Angle _____.
As you manipulate the intersecting lines by moving Points A and C, what observations do you make about a linear pair of angles?
How about if you add the linear pair of angles, do you notice something then?