

Polygon
From Greek: polys "many" + gonia "angle"
Definition: A number of
coplanar
line segments, each connected end to end to form a closed shape.
Try this Drag the orange dots on each vertex
to reshape the polygon. It is initially an irregular polygon; change it by clicking on "make regular", and change the number of sides.
Polygons are one of the most allencompassing shapes in geometry. From the simple triangle up through squares, rectangles,
trapezoids, to dodecagons and beyond.
In the figure above click on "make regular" and then gradually change the number of sides to see familiar shapes.
Types of Polygon
Properties of all Polygons (regular and irregular)
Properties of Regular Polygons
Named Polygons
Many polygons have names based on the number of sides. A 5sided polygon is called a pentagon for example.
There are some that wish to name every possible polygon, but there seems little point in doing so.
For example a 42sided polygon is called a "tetracontakaidigon".
Beyond about 10 sides, most people call them an "ngon". For example a 15gon has 15 sides. This seems easier to remember and understand.
However, there are some names that do occur in everyday experience:
But if you would prefer to call a heptagon a 7gon for example, that's fine. Everyone will know what you mean.
Other polygon topics
General
Types of polygon
Area of various polygon types
Perimeter of various polygon types
Angles associated with polygons
Named polygons
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