# G.1.20.3 An Alternate Explanation

## Here are intersecting lines AE and CD:

Rotate line *AE *and points* A, B, *and* E* by 180 degrees around point *C*. Label the images of *A, B, C, D, E *as *A', B', C', D', E'.
*What is true about lines *AE* and *A'E'*? Explain your reasoning.

What is true about angle *CBE* and angle *CB'E'*, explain how you know.

Angles *CBE* and CB'E' have a special name -- they are called Alternate Interior Angles.
Name another pair of Alternate Interior Angles.

What is true about angle *ABC* and angle *CB'E'*, explain how you know.

Angles *ABC* and *CB'E'*' have a special name -- they are called Consecutive (Same Side) Interior Angles.
Name another pair of Consecutive Interior Angles.

What is true about angle *DBE* and angle *D'B'E'*, explain how you know.

Angles *DBE* and *D'B'E'* have a special name -- they are called Alternate Exterior Angles.
Name another pair of Alternate Exterior Angles.