1. Polygons Closed figure made up of line segments
Concave Polygon-can have reflex angles :One or more angles greater than 180o
Convex Polygon-all angles greater than 0o and less than 180o

2. congruent
Same size and same shape

3. similar
Same shape, not necessarily the same size

4. Regular Polygons
Polygon with all sides congruent and all angles congruent
Special Regular Polygons
Equilateral triangle
Square

5. Triangle
Polygon with three sides A B C
Symbol: ABC

6. Quadrilateral Polygon with four sides quadrilateral trapezoid
parallelogram
kite
rectangle
rhombus
square

7. Parallelogram
Quadrilateral with opposite sides parallel and congruent

8. Rectangle
Parallelogram with four right angles

9. Rhombus
Parallelogram with four congruent sides

10. Square
Parallelogram with four right angles and four congruent sides

11. Trapezoid
Quadrilateral with one pair of parallel sides

12. Pentagon
Polygon with five sides
Regular Pentagon

13. Hexagon
Polygon with six sides
Regular Hexagon

14. Heptagon
Polygon with seven sides
Regular Heptagon

15. Octagon
Polygon with eight sides
Regular Octagon

16. Decagon
Polygon with ten sides
convex
concave

17. Dodecagon
Polygon with twelve sides
convex
concave

18. Total Degrees in Polygons
Figure
Sides 3
# of triangles
1 x 180 =
Total degrees
1800 4
2 x 180 =
3600 5
3 x 180 =
5400
180
180
180
180
180
180

19. Complete the Table Do you see a pattern?
Figure
Sides
# of triangles
Total degrees 6 7 8 12 n

20. Regular Polygons
All sides congruent
All angles congruent

21. Angle Measure Regular Polygons
What is degree measure of each angle of a regular polygon? E
5400
Total degrees = ?? A D
Degrees = ??? C B A
1080 E D B C

22. Angle Measure Regular Polygons
Equilateral triangle = Measure each angle = 600
Square = Measure each angle = 900

23. Angle Measure Regular Polygons
Regular Hexagon = ?? Measure each angle = ??
Regular Octagon = ?? Measure each angle = ??

24. Polygons
The End