1. Geometry Agenda 1. ENTRANCE 2. Go over Practice 3. Quiz 4. 3-4 The Polygon Angle-Sum Theorems 5. Practice Assignment 6. EXIT

2. Practice

3. Quiz Time Good Luck!!!

4. Chapter 3 3-4 The Polygon Angle-Sum Theorems

5. Polygon A _______ figure that consists of three or more segments joined at the endpoints and each segment must meet exactly two other segments.

6. Polygon Terms 3 sidesTriangle 4 sidesQuadrilateral 5 sidesPentagon 6 sidesHexagon 7 sidesHeptagon 8 sidesOctagon 9 sidesNonagon 10 sidesDecagon 11 sidesUndecagon 12 sidesDodecagon n sidesn-gon

7. Naming A Polygon A polygon is named by the number of _______. ex: If a polygon has ___ sides, you use ___ letters. Polygon ABCDE

8. Types of Polygons Convex –The diagonals are entirely inside the figure. Concave –At least one diagonal is partly outside the figure.

9. Regular Polygon Remember: equilateral, equiangular A regular polygon is a polygon that is both equilateral and equiangular.

10. Theorem 3-9 Polygon Angle-Sum Theorem The sum of the measures of the angles of an n-gon is (n-2)180. ex: This pentagon has 5 sides.

11. Theorem 3-10 Polygon Exterior Angle-Sum Theorem The sum of the measures of the ________ angles of a polygon, one at each vertex, is 360 . ex: This pentagon has 5 sides. The sum of the 5 exterior angles is 360 .

12. Example #1 Name the ________. Identify vertices, sides, and angles. Is it concave or convex?

13. Example #2 Find the interior angle sum. a. 13-gonb. decagon

14. Example #3 How many sides does each polygon have if its interior angle sum is: a. 2700  b. 1080 

15. Example #4 Find x.

16. Example #5 Find y.

17. Example #6 Find x.

18. Example #7 Find x.

19. Example #8 Find x.

20. Example #9 How many sides does each regular polygon have if its exterior angle is: a. 120  b. 24 

21. Example #10 How many sides does each regular polygon have if its interior angle is: a. 90  b. 144 

22. Practice –WB 3-4 # 1-19 EXIT