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# concave octagon with the least number of internal diagonals

4 replies to this topic

### #1 Perhaps check it again

Perhaps check it again

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Posted 13 July 2014 - 07:03 PM

Consider concave octagons in the plane that are non-self-intersecting.

What is the minimum number of diagonals possible for one of these octagons

if it is required that each of the diagonals lie entirely within the octagon?

Edited by Perhaps check it again, 13 July 2014 - 07:05 PM.

• 0

### #2 nana77

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Posted 13 July 2014 - 07:24 PM

Spoiler for hmm

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### #3 Perhaps check it again

Perhaps check it again

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Posted 13 July 2014 - 10:11 PM

nana77, I don't see that number of yours coming up.

Maybe if you shared even some nonspecific thoughts as to why you

think it is the number you stated, it would lead me to give (possibly needed)

clarifications.

I am open to some other possible answers other than the one I have in mind,

but I want to know if someone is making some more/different assumptions

about the problem than the ones I have stated in the original post.

The problem is still open.

Edited by Perhaps check it again, 13 July 2014 - 10:12 PM.

• 0

### #4 nana77

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Posted 13 July 2014 - 11:03 PM

minimum means lowest number, hence 0.

Maximum would be more of a challenging question, I think

• 0

### #5 bonanova

bonanova

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Posted 14 July 2014 - 02:02 AM

Spoiler for Looks like

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Vidi vici veni.

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