July 2019
 

[url]http://www.research.ibm.com/haifa/ponderthis/challenges/July2019.html[/url]

[QUOTE]
Exactly two edges meet at each vertex
[/QUOTE]

[url]https://en.wikipedia.org/wiki/Simple_polygon[/url]

Unless there is no distinction between a "Weakly simple polygon" and a "Simple Polygon".

[QUOTE]This formalizes the notion that such a polygon allows segments to touch but not to cross.[/QUOTE]

[QUOTE=a1call;520419][url]https://en.wikipedia.org/wiki/Simple_polygon[/url]

Unless there is no distinction between a "Weakly simple polygon" and a "Simple Polygon".[/QUOTE]

Based on past experience of clarifications coming in later, you may safely assume simple means just simple, so "Exactly two edges meet at each vertex"

Can 3 (consecutive) points lie in a straight line?

With "Weakly simple polygon" your interpretation is as good as mine if not better. But I don't read any restrictions other than crossing lines.

[QUOTE=axn;520439]Can 3 (consecutive) points lie in a straight line?[/QUOTE]

Why not

LOL. The best answer I got was exactly a difference of 7 (several polygons with area 8 and several with area 15).

Well, being a chess player, mathematician and not to mention smart, does give you an unfair advantage.
But at least you didn't have to use your programming skills this time.:smile:

[QUOTE=axn;520451]LOL. The best answer I got was exactly a difference of 7 (several polygons with area 8 and several with area 15).[/QUOTE]

On a related note to the previous question asked: Do you have a solution with no straight line?

[QUOTE=SmartMersenne;520486]On a related note to the previous question asked: Do you have a solution with no straight line?[/QUOTE]
there is one without 3 consecutive points in a row.

I have confirmation. The polygons should not be weakly-simple.