Exterior Angles

Author:
Monica
<AEB is called an exterior angle. Make a table of values using "ArcAB", "ArcCD", "ArcAB-ArcCD", and "<AEB" for the columns. Adjust point A or B and record the values in each column. Repeat the last step four more times. Is there a pattern you notice between the 3rd and 4th column? How could you write a formula describing the pattern you noticed?