0
$\begingroup$

According to the definition of Polygon, If a Poly-line's first and last points are connected then it is called Polygon. See the image below. I have P1, .... P5 Polyline. If I draw a line from P5 to P1 then it will be called polygon or not? I am confused here.

enter image description here

  • 0
    @user960567 : It means that some people would call that a polygon. Personally I don't think it's important to make a distinction, but if for you it is then some people agree that it can be considered a polygon. I have no idea if it's a good idea or not to do so, but I usually refer to polygons as non-degenerate ones.2012-08-13

1 Answers 1

2

I think conventionally you would expect the area of a polygon to be non-zero.

Generally your lecturer/teacher should specify in lectures the exact definition of things, and you should use that to answer his/her questions. If you find loopholes you should ask them about it.

According to the link for Wikipedia you supplied:

In geometry a polygon is a flat shape consisting of straight lines that are joined to form a closed chain or circuit.

Digging a little deeper you can find this at http://en.wikipedia.org/wiki/Closed_polygonal_chain:

In some cases it is important to draw a distinction between a polygonal area and a polygonal chain.