1. Polygons Quadrilateral Triangles Pentagon Polygon Song Heptagon
Hexagon
Decagon
Octagon

2. Definition of Polygon
A number of coplanar (on the same plane) line segments, each connected end to end to form a closed shape.
Where do we find polygons in nature?

3. Triangles
A triangle is a closed polygon with three segments that are linked end-to-end

4. Scalene Triangle
A triangle where all three sides are different in length

5. Isosceles Triangle
A triangle which has two sides equal in length

6. Right Triangle
A triangle where one of its interior angles is a right angle (90⁰ angle)

7. Equilateral Triangle
A triangle which has all three of its sides equal in length

8. Quadrilaterals
For coplanar (on the same plane) line segments linked end to end to create a closed figure. Also a four-sided polygon

9. Square
A four sided polygon with all sides equal and all internal angles 90⁰

10. Rectangle A four sided polygon where all interior angles are 90⁰
What is the difference between a rectangle and a square?
A square has equal lengths while a rectangle does not

11. Rhombus A quadrilateral with all four sides equal in length
Is a square a rhombus? Why?
A square has four sides equal in length it is different because it has equal angles but it is a rhombus

12. Pentagon A polygon with 5 sides
Pentagons are found in soccer balls, also the famous building in Washington D.C

13. Hexagon
A polygon with 6 sides
Hexagons are found in bee hives

14. Heptagon
A polygon with 7 sides

15. Octagon
A polygon with 8 sides

16. Decagon
A polygon with 10 sides

17. Polygon Song
Polygons are on a plane Simple, closed, with many a name Line segments for every side Nothing curved can we abide “3” sided are Triangles “4” sided we call Quadrilateral “5” is known as a Pentagon Just like the building in Washington Chorus Think “X” for “6” and Hexagon Cool is “7” Heptagon Octagons have sides of eight Look like stop signs, not home plate
Chorus
“9” is for a Nonagon
Don’t really use then except in song
“10” sides make a Decagon
Now we know our Polygons!
Chorus:
Don’t use: 1, 2
Start with: 3, 4
Keep going: 5, 6, 7, 8

18. Nonagon A nine sided polygon
We don’t use nonagons often so we don’t need to know them for this class