lar polygons, but rather to anytwo-dimensional closed figure with the number of
sides as described by its name. For example, the two figures shown above are both
pentagons—A is a regular hexagon and B is an irregular hexagon.
Polygons are described in other ways, too. Convex polygonsare those in which
every line drawn between any two points inside the polygon lie entirely within the fig-
ure. Opposite from the convex polygons are the concave polygons—those that are
essentially “caved in,” with some of the sides bent inward. If a line is drawn between
two points inside a concave polygon, the line often passes outside the figure. Another
type of polygon is a star polygon,in which a star figure is drawn based on equidistant
points connected on a circle.What are the namesgiven to regular polygons?
Polygons are classified according to the number of sides they have. A polygon with n
sides is called an n-gon. The following lists some of the names of polygons, depending
on the number of sides. It is also possible to substitute “n-gon,” when the name is not
known (for example 14-gon or 20-gon).Names for Regular Polygons
Sides Polygon Name
3 trigon or triangle
180 4 quadrilateral or tetragon
Examples A, B, and C above are polygons, while
examples D and E are not.Types of polygons include regular hexagons (A),
irregular hexagons (B), convex polygons (C), and
concave polygons (D).