From Greek deka "ten" + gonia "angle"
Definition: A polygon
with 10 sides
Adjust the decagon below by dragging any orange dot. By clicking on the top left command line,
you can switch it between a
Properties of regular decagons
Properties of all decagons
|Number of diagonals
||The number of distinct diagonals possible from all vertices. (In general ½n(n–3) ).
In the figure above, click on "show diagonals" to see them.
See Diagonals of a Polygon
|Number of triangles
||The number of triangles created by drawing the diagonals from a given vertex. (In general n–2).
In the figure above, click on "show triangles" to see them. See Triangles of a Polygon
|Sum of interior angles
||In general 180(n–2) degrees .
See Interior Angles of a Polygon
Other polygon topics
Types of polygon
Area of various polygon types
Perimeter of various polygon types
Angles associated with polygons
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