Generally, the word
polygon is used to refer to a two dimensional construction that encloses a space using straight lines. Regular polygons have sides that are of equal length and have equal angles between each side. [Concave polygon]
?s have at least one internal angle that is greater than 180°, whereas convex polygons have all internal angles less than 180°. A cyclic polygon has all of its vertexes lying on the same circle. A polygon can belong to several classifications simultaneously; a square is a regular, convex, cyclic polygon, for example.
'Poly-' is from the Greek word for 'many' and '-gon' is a Greek combining form meaning 'angle'. Strictly speaking, every polyhedron is also a polygon as is every polytope, since they all have angles.
Regular Polygons
Name | Sides | Angle* |
Triangle | 3 | 60° |
Square | 4 | 90° |
Pentagon | 5 | 108° |
Hexagon? | 6 | 120° |
Septagon | 7 | 128.57° |
Octagon | 8 | 135° |
Nonagon | 9 | 140° |
Decagon | 10 | 144° |
Hectagon | 100 | 176.4° |
Megagon | 106 | 180.° (approx.) |
Googolgon | 10100 | 180.° (approx.) |
* Angle= 180°-(360°/ Sides )