There is no such word as a dectagon. And since it could refer to an octagon or a decagon (or possibly something else), it is not possible to give a sensible answer. Please correct your spelling and resubmit the question. Also it would be useful to know how many WHAT?
A decagon has 10 sides
A decagon has 10 sides
There are 10 sides on a decagon
Its not a do-decagon its a dodecahedran!!
Decagon is 10 sides. Octagon is 8 sides.
A decagon has 10 sides. It also have 10 angles.
A decagon has 10 sides.
A decagon has 10 sides
10 sides.
A decagon has 10 sides, and a quadrilateral has 4 sides, therefore a decagon has 6 more sides than a quadrilateral.
It has 10 sides
10 sides