Is Figure a Polygon? Examining Edges of the Image

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Discussion Overview

The discussion revolves around whether a specific figure can be classified as a polygon, particularly focusing on the nature of its edges and vertices. Participants explore definitions of polygons, including the distinction between simple and self-intersecting polygons, and the implications of including certain line segments as edges.

Discussion Character

  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants propose that the figure can be described as a polygon, but not a "simple polygon," as it intersects itself.
  • There is a suggestion that the middle line segment could be counted as two edges, depending on how the points are labeled.
  • One participant questions whether the figure fulfills the criteria for being a polygon, emphasizing the need to close the loop by returning to the starting point.
  • Another participant expresses that the question may not have a definitive answer, depending on how one defines a polygon and whether straight angles are allowed.

Areas of Agreement / Disagreement

Participants do not reach a consensus on whether the figure qualifies as a polygon. Multiple competing views exist regarding the definitions and criteria for polygons, particularly concerning self-intersection and edge classification.

Contextual Notes

There are limitations in the discussion regarding the definitions of polygons, the treatment of angles, and the necessity of closing the loop in polygonal structures. These aspects remain unresolved.

Suyogya
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Can someone please tell is this (https://ibb.co/stGFSKs) figure a polygon. If yes then is the middle line would count as an edge?

15487814949745525543992389032260.jpg
 

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Yes, it could be described as a polygon - but not a "simple polygon".
https://en.wikipedia.org/wiki/Polygon

If the left edge from top to bottom is A, B, D and the right edge from top to bottom is A, C, E:
Then this could be described as polygon ABCBDECA or ABCEDCDA.

Thus, it would be a polygon that intersects itself.
polygons that do not intersect themselves are called "simple polygons".

Oh, and to answer your follow-on question: The middle line segment would be two edges.
 
.Scott said:
Yes, it could be described as a polygon - but not a "simple polygon".
https://en.wikipedia.org/wiki/Polygon

If the left edge from top to bottom is A, B, D and the right edge from top to bottom is A, C, E:
Then this could be described as polygon ABCBDECA or ABCEDCDA.

Thus, it would be a polygon that intersects itself.
polygons that do not intersect themselves are called "simple polygons".

Oh, and to answer your follow-on question: The middle line segment would be two edges.
let be name the points as,(https://ibb.co/2srLjB1) if AC would be an edge then A and C are vertices and segments BC, AC, AD, CE became edges. Is this justified Also for a simple polygon there should be no self intersecting edge, the line AC just touches the lines BD and BE, is this sufficient to fulfill the intersecting condition?
 
.With your new point labels, the polygon would be either BACADECB or BADECACB.
In order for it to be a polygon, you need to close the loop - end at the same place you started.
I am not sure I am interpreting your statements correctly, but it doesn't sound as though you are following that rule.
 
Suyogya said:
Can someone please tell is this (https://ibb.co/stGFSKs) figure a polygon. If yes then is the middle line would count as an edge?
To me, the question isn't answerable: either you define a polygon one way or the other, either allow straight angles or don't.
 
.Scott said:
.With your new point labels, the polygon would be either BACADECB or BADECACB.
In order for it to be a polygon, you need to close the loop - end at the same place you started.
I am not sure I am interpreting your statements correctly, but it doesn't sound as though you are following that rule.
thanks for correcting
 

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