It can be convex or concave.
The sum of the exterior angles of ANY polygon, convex or concave, is 360 degrees.
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.
it's a decagon.
It can be convex or concave.
Yes, it can.
In 2-d, the naming of polygons is such that a 10 sided shape is a decagon. Even if it is a 5-pointed star shape, it is a decagon. A concave decagon (rather than convex) but still a decagon. In 3-d, a decahedron, possibly, with the term "sides" being used for "faces".
Yes, but only in the form of some irregular concave decagons.
concave decagon
Yes. For example if you have a decagon in which the top, bottom and the four sides on the left are as in a regular decagon, and if the four sides on the right make the shape concave. These decagons will "slot" into one another.
The sum of the exterior angles of ANY polygon, convex or concave, is 360 degrees.
A 'concave decagon' is a ten-sided shape with every other corner pushed in towards the centre. It forms a regular five-pointed star.
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.