A decagon is a ten-sided polygon. Several special types of decagons are illustrated above. In particular, a decagon with vertices equally spaced around a circle and with all sides the same length is a regular polygon known as a regular decagon.
Decagon
See also
Hexagon, Octagon, Pentagon, Polygon, Regular Decagon Explore this topic in the MathWorld classroomExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Decagon." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Decagon.html