A decagon (not a decadon) is a ten-sided shape.
a quadtriple decadon
Each of the 10 sides of the decagon is 1.9314 inches long.
The correct spelling is Dodecahedron and it has 30 edges.* * * * *The correct spelling for a shape with 12 faces is, indeed, dodecahedron. But the question is about a shape with 10 faces, for which the spelling IS correct.Unfortunately, that is as far as we can go. There are many possible configurations for a decahedron and they have different numbers of edges:For example:A nonagon based pyramid: 18 edgesAn octagonal prism : 24 edgesA pentagonal dipyramid: 15 edges.