The document defines and classifies different types of polygons based on the number of sides. It explains that a polygon is a closed plane shape with 3 or more straight sides and no curves. Various polygons are then defined based on their number of sides, from triangles with 3 sides to dodecagons with 12 sides. The document also distinguishes between convex and concave polygons and defines regular polygons as those with all equal side lengths. It concludes by noting that two polygons are similar if they have the same angles in the same positions, regardless of side length.

1. Polygons Brought to you by Cavis for President

2. What is a Polygon???? Any ideas? Write down what you think it is for #1.

3. A polygon is a closed plane figure with 3 or more sides (all straight lines, no curves).

4. Classifying Polygons by # of Sides 3 sided Polygon = Triangle Hint: Think “Tri”cycle, “tri”pod, “Tri”lateration (Tri means 3)

5. Classifying Polygons by # of Sides 4 sided Polygon = Quadrilateral Hint: Think “Quad”rant, “Quad”ruple, “Quad” (AKA 4-Wheeler)

6. Classifying Polygons by # of Sides 5 sided Polygon = Pentagon Hint: Think “Pent”athalon, or the government building “The Pentagon”

7. Classifying Polygons by # of Sides 6 sided Polygon = Hexagon Hint: Both “Hexagon” and “Six” have an ‘x’ in them

8. Classifying Polygons by # of Sides 7 sided Polygon = Heptagon Hint: ???

9. Classifying Polygons by # of Sides 8 sided Polygon = Octagon Hint: “oct”opus – 8 legs

10. Classifying Polygons by # of Sides 9 sided Polygon = Nonagon Hint: “Non” is similar to “Nine”

11. Classifying Polygons by # of Sides 10 sided Polygon = Decagon Hint: Think “Dec”ade (10 years

12. Classifying Polygons by # of Sides 11 sided Polygon = Hendecagon Hint: ???

13. Classifying Polygons by # of Sides 12 sided Polygon = Dodecagon Hint: ???

14. Classifying Polygons by # of Sides Q: What do we call a polygon with more than 12 sides? A: An ‘n’-gon where ‘n’ is the number of sides Ex: a 20 sided polygon is a 20-gon

15. Classifying Polygons by # of Sides Dodecagon 12 Hendecagon 11 Decagon 10 Nonagon 9 Octagon 8 Heptagon 7 Hexagon 6 Pentagon 5 Quadrilateral 4 Triangle 3 Name # of Sides

16. Two Types of Polygons Convex – all vertices point outward Concave – at least one vertex points inward towards the center of the polygon (The side looks like it “caved” in)

17. Regular Polygons A Regular Polygon is a polygon in which all sides are the same length. Equilateral Triangle   Square

18. Review of Similar Triangles • 2 Triangles are similar if they have the same shape (i.e. the same angle in the same positions)

19. Similar Polygons The same is true of polygons. 2 polygons are similar if they have the same angles in the same positions (i.e. same shape) ^ Similar Pentagons ^ Similar Trapezoids  Similar Rectangles 