There is no such thing as a 3-D decagon.
No. A decagon is two-dimensional.
Decogon * * * * * A decagon, actually.
a decagon
a hen decagon
2D is a decagon. 3D is a decahydron.
2D shape = Decagon 3D shape = Decahedron
It depends on whether or not the decagon is a perfect decagon or a complex decagon. However, a perfect decagon has no acute angles.
decagon
Decagon
The anwser is a Decagon.
No, a decagon is not a quadrilateral.