Types of

Polygons

1. Simple and complex polygons

• A simple polygon has only one boundary

and the sides do not cross each other,

otherwise it is a complex polygon.

• Simple polygon

• Complex polygon

2. Concave and convex polygons

• A convex polygon has no internal angle

more than 180º and if there are any

internal angles greater than a straight

angle, then it is a concave polygon.

• Concave polygon

• Convex polygon

3. Regular and Irregular polygons

• Regular polygon is one whose sides are all

equal and whose interior angles are all

congruent. Thus, a regular polygon is both

equilateral and equiangular. If, otherwise, the

polygon is said to be irregular polygon.

• Regular polygon

• Irregular polygon

• Irregular polygon

NAMES OF

POLYGONS

• Polygons are named or classifiedaccording to their number ofsides. A polygon with n sides iscalled n-gon.

n (sides) Polygon

3 Triangle, trigon

4 Quadrilateral, tetragon

5 Pentagon

6 Hexagon

7 Heptagon

8

9

Octagon

Nonagon, enneagon

10 Decagon

1

2 Digon

Henagon

Sides Polygon

11 Hendecagon

12 Didecagon

Tridecagon13

14 Tetradecagon

15 Pentadecagon

16 Hexadecagon

17 Heptadecagon

18 Octadecagon

19 Enneadecagon

20 Icosagon

• To construct a polygon’s name, combine the

corresponding prefix and suffix.

Example:

Construct the name for 28 and 46 sided

polygons.

20

Sides Prefix

Icosa

Sides Suffix

8 Octagon

Icosaoctagon

Sides Prefix Sides Suffix

40 tetracon 6 hexagon

Tetraconhexagon