Polygons Lesson

POLYGONS

POLYGONS

Polygon comes from Greek. Poly- means "many" and -gon means "angle".Polygons are 2-dimensional shapes. They are made of straight lines, and the shape is "closed" (all the lines connect up).

TYPES OF POLYGON

​Regular polygons have all sides and angles are equal but an irregular polygon does not have all sides and angles equal.

- Regular Polygons

- Irregular Polygons

​Name	​Sides	​Angle
​Triangle or Trigon	​3	​60°
​Quadrilateral or Tetragon	4​	​90°
​Pentagon	5​	​108°
Hexagon​	6​	​120°
Heptagon or Septagon​	7​	​128.57°
Octagon​	8​	​135°
Nonagon​ or Enneagon	9​	​140°
​Decagon	10​	​144°
​Hendedecagon or Undecagon	11​	​147.27°
​Dodecagon	12​	​150°
Triskaidecagon	13	152.31°

​Name	​Sides	​Angle
​Tetrakaidecagon	​14	​154.29°
Pentadecagon​	15​	156°
Hexakaidecagon​	16​	​157.5°
Heptadecagon​	17​	​158.82°
Octakaidecagon​	18​	​160°
Enneadecagon​	19​	​164.05°
Icosagon​	20​	​162°