decagon

• By my count, our imaginary boxing ring is a decagon. —  elliott.org
• "Out of the way, I'm in a hurry to buy more decagon records!" —  Aussie-Nintendo.com Forums
• The exterior angles in a convex polygon always add up to 360°. 360° / 36° = 10 angles, so that means you have a decagon. —  Yahoo! Answers: Latest Questions
• All three sides of the same length, three angles equal (60 degrees). quadrilateral, quadrangle, tetragon quadrangle and tetragon are not common usages parallelogram both pairs of non-adjacent sides are parallel rhombus equilateral (also a parallelogram) decagon —  Citizendium, the Citizens' Compendium - Recent changes [en]
• Q. Why is it called a decagon? —  The Infant System For Developing the Intellectual and Moral Powers of all Children, from One to Seven years of Age

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