1. In your journal, create this chart PolygonNumber of Angles Sum of degrees Place your tan homework on your desk

2. Expectations Explain how the formula for the sum of angles of a polygon is derived Compute problems regarding the sum of angles of a polygon

3. How many degrees in the sum of the interior angles of a triangle? 180 Degrees

4. Add the data to the chart PolygonNumber of Angles Sum of degrees Triangle3180

5. How many degrees in the sum of the interior angles of a quadrilateral? 360 Degrees

6. Add the data to the chart PolygonNumber of Angles Sum of degrees Triangle3180 Quadrilateral4360

7. How many degrees in the sum of the interior angles of a pentagon? 330 + 210 = 540

8. Add the data to the chart PolygonNumber of Angles Sum of degrees Triangle3180 Quadrilateral4360 Pentagon5540

9. Add the data to the chart PolygonNumber of Angles Sum of degrees Triangle3180 Quadrilateral4360 Pentagon5540 Hexagon6710

10. Add the data to the chart PolygonNumber of Angles Sum of degrees Triangle3180 Quadrilateral4360 Pentagon5540 Hexagon6710 Heptagon7890

11. Look for a pattern PolygonNumber of Angles Sum of degrees Triangle3180 Quadrilateral4360 Pentagon5540 Hexagon6710 Heptagon7890 + 180 The sum of the degrees increases 180 degrees for every additional angle

12. Look for a pattern PolygonNumber of Angles Sum of degrees Triangle3180 Quadrilateral4360 Pentagon5540 Hexagon6710 Heptagon7890 What is the relationship between the number multiplied by 180 and number of sides of a triangle? 2 x 180 = 3 x 180 = 4 x 180 = 5 x 180 = 1 x 180 =

13. Look for a pattern PolygonNumber of Angles Sum of degrees Triangle3180 Quadrilateral4360 Pentagon5540 Hexagon6710 Heptagon7890 What is the relationship between the number multiplied by 180 and number of sides of a triangle? 2 x 180 = 3 x 180 = 4 x 180 = 5 x 180 = 1 x 180 = or Number of angles – 2 times 180 = sum of degrees (n-2)180 = Sum of degrees

14. What is the sum of all the angles of an octagon? (n-2)180 = Sum of degrees (8-2)180 = Sum of degrees (8-2)180 = Sum of degrees 6 x 180 = 1080

15. What is the sum of all the angles of an nonagon? (n-2)180 = Sum of degrees (9-2)180 = Sum of degrees (9-2)180 = Sum of degrees 7 x 180 = 1260

16. Record formula in journal PolygonNumber of Angles Sum of degrees Triangle3180 Quadrilateral4360 Pentagon5540 Hexagon6710 Heptagon7890 (n-2)180 = Sum of degrees