A polygon is a closed shape that has three or more sides. Each side is a line segment. The line segments form the sides of the polygon.
The following are examples of polygons:
The following figures are not polygons:
The sides of a simple polygon do not intersect. In a simple polygon, the line segments meet in pairs to form the vertices. Usually the word "simple" is omitted and the word "polygon" is used to mean "simple polygon".
A complex polygon has intersecting sides.
A convex polygon has all angles less than 180 ° .
A concave polygon has at least one angle greater than 180°. (memory tool: concave has a "cave" in it)
An equilateral polygon is a polygon which has all sides of the same length. A rhombus is an example of an equilateral polygon.
An equiangular polygon is a polygon whose interior angles are equal. A rectangle is an example of an equiangular polygon
A regular polygon is a polygon with equal sides and equal angles otherwise it is an irregular polygon. A regular polygon is both equilateral and equiangular.
Some polygons have special names, depending on the number of sides they have.
Number of sides
Name of polygon
For polygons with more sides, it is easier and quite common to use a number to indicate the number of sides. For eg. 15-gon or 23-gon.
Practice the names of polygons with the following worksheets
Names of Polygons - Give the number of sides
Names of Polygons - Give the names of polygons
The following video will show you how to define a polygon, how to distinguish between concave and convex polygons, how to name polygons.
Rotate to landscape screen format on a mobile phone or small tablet to use the Mathway widget, a free math problem solver that answers your questions with step-by-step explanations.
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