1. EXTERIOR ANGLES OF A POLYGON Polygons

2. An exterior angle of a regular polygon is formed by extending one side of the polygon. Angle CDY is an exterior angle to angle CDE Exterior Angle + Interior Angle of a regular polygon =180 0 D E Y B C A F 1 2 Polygons

3. 120 0 60 0 Polygons

4. 120 0 Polygons

5. 120 0 Polygons

6. 360 0 Polygons

7. 60 0 Polygons

8. 60 0 Polygons

9. 1 2 3 4 5 6 60 0 Polygons

10. 1 2 3 4 5 6 60 0 Polygons

11. 1 2 3 4 5 6 360 0 Polygons

12. 90 0 Polygons

13. 90 0 Polygons

14. 90 0 Polygons

15. 1 2 3 4 360 0 Polygons

16. No matter what type of polygon we have, the sum of the exterior angles is ALWAYS equal to 360º. Sum of exterior angles = 360º Polygons

17. In a regular polygon with ‘n’ sides Sum of interior angles = (n -2) x 180 0 Exterior Angle + Interior Angle =180 0 Each exterior angle = 360 0 /n No. of sides = 360 0 /exterior angle Polygons

18. Let us explore few more problems Find the measure of each interior angle of a polygon with 9 sides. Ans : 140 0 Find the measure of each exterior angle of a regular decagon. Ans : 36 0 How many sides are there in a regular polygon if each interior angle measures 165 0 ? Ans : 24 sides Is it possible to have a regular polygon with an exterior angle equal to 40 0 ? Ans : Yes Polygons