1. Objective: I will investigate the measures of the interior and exterior angles of polygons

2. Find the sum of the measures of the interior angles of each convex polygon A. 32-gonB. 18-gonC. 19-gon D. 27-gonE. 4y-gonF. 2x-gon

5.  An exterior angle is formed when one side of the polygon is extended at each vertex.  Note: the measure of one interior plus one exterior always equals 180 degrees because they are a linear pair!!!

8.  Exterior Angle sum example Exterior Angle sum example

10. 1. What is the measure of each exterior angle of a regular decagon? 2. What is the measure of each exterior angle of a regular octagon? 3. What is the measure of each exterior angle of a regular heptagon? 4. What is the measure of each exterior angle of a regular 18-gon?

12.  If each exterior angle of a regular polygon has a measure of 15 degrees. How many sides does the polygon have?  If each exterior angle of a regular polygon has a measure of 20 degrees. How many sides does the polygon have?  If each exterior angle of a regular polygon has a measure of 36 degrees. How many sides does the polygon have?

14.  If an interior angle of a regular polygon has a measure of 135 degrees, how many sides does the polygon have?  If an interior angle of a regular polygon has a measure of 60 degrees, how many sides does the polygon have?  If an interior angle of a regular polygon has a measure of 144 degrees, how many sides does the polygon have?

15.  Homework: practice worksheet