There are 10 sides on a decagon.
http://wiki.answers.com/Q/How_many_sides_are_on_a_...

A decagon is a plane polygon of 10 angles and 10 sides. Thanks for using ChaCha!
http://www.chacha.com/question/howmanysidestoa...

Formulas related to regular polygons can be found at: ============================================================ For a regular decagon we can inscribe a circle which touches all
http://en.allexperts.com/q/Geometry2060/DecagonD...

A decagon is a polygon having ten angles and ten sides. Its internal angles add up to 1440 degrees.
http://www.kgbanswers.com/howmanysidesdoesade...
