1. Regular Polygons

2.  Polygons are a enclosed flat (on the same plane) shape.

3.  Triangle has 3 sides  Quadrilateral has 4 sides  Pentagon has 5 sides  Hexagon has 6 sides  Heptagon has 7 sides  Octagon has 8 sides  Nonagon has 9 sides  Decagon has 10 sides  Hendecagon has 11 sides  Dodecagon has 12 sides

4.  All angles are equiangular and all sides are equilateral. ( Meaning all the side and angles are the same size )

5.  To find the total number of degrees inside any polygon use the formula below.

6.  Triangle has 3 sides, 180 degrees  Quadrilateral has 4 sides, 360 degrees  Pentagon has 5 sides, 540 degrees  Hexagon has 6 sides, 720 degrees  Heptagon has 7 sides, 900 degrees  Octagon has 8 sides, 1080 degrees  Nonagon has 9 sides, 1260 degrees  Decagon has 10 sides, 1440 degrees  Hendecagon has 11 sides, 1620 degrees  Dodecagon has 12 sides, 1800 degrees

7. A E D C B

8.  To calculate a single exterior angle of a regular polygon use the formula below.

9.  The name of the polygon WATER is a _____________ If ∠W =(3x +1)°, ∠A=(2x+9)°, ∠T=(2x+10)°, ∠E=(x+128)°, and ∠T=(x+131)°, then determine the size of each angle.  Solution Solution A R E T W

10.  What is the size of an exterior angle of a Dodecagon?