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