Talk:Euclidean geometry

There are no axioms or postulates in Euclid's Elements

This article is factually wrong. There are no axioms or postulates in Euclid's Elements.

There are no axioms or postulates in Euclidean geometry. Every "requirement" is well defined from the first, that is, a straight line can be drawn between any two points.

Read my article:

https://drive.google.com/open?id=0B-mOEooW03iLRjVxZERCa2R5Tlk

Play with the dynamic applets:

https://www.youtube.com/watch?v=kzcVmXVpk-g

https://www.youtube.com/watch?v=ARzchjd8eZg — Preceding unsigned comment added by 104.219.113.199 (talk) 15:53, 14 April 2017 (UTC)

New Video: https://www.youtube.com/watch?v=5BvgrMEc-E0 — Preceding unsigned comment added by 173.167.44.217 (talk) 00:58, 2 March 2018 (UTC)

GA Review

This review is transcluded from Talk:Euclidean geometry/GA1. The edit link for this section can be used to add comments to the review.

Hello. I am going to have to fail this article's GA nomination, due mainly to referencing issues, but also to a few other things. Here is a list of the major issues that need to be addressed:

• The main problem is that the article is severely under-referenced. There are many sections that completely lack references, and most sections have at least one paragraph that is unreferenced.

Added a bunch of references.--76.167.77.165 (talk) 01:39, 26 February 2009 (UTC)

• Web references need to be formatted with a publisher and access date at the very least.

Done.--76.167.77.165 (talk) 01:39, 26 February 2009 (UTC)

• The references section has two books listed in the bullet point part that aren't present in the in-line references. Books that aren't used for in-line references should be removed altogether or moved to a "Further reading" section.

Fixed.--76.167.77.165 (talk) 22:14, 25 February 2009 (UTC)

• There are a lot of really short paragraphs and really short sections. These need to be either expanded or combined. As they are, they make the article look very choppy and harder to read.
• The Euclid proof image in the Axiomatic treatment section needs some tweaks made to its licensing.

Can you explain what the necessary tweaks are? It's not obvious to me what the problem is.--76.167.77.165 (talk) 22:14, 25 February 2009 (UTC)

If you go to the image page, the license says "Note: This tag should not be used anymore!", and then gives a list of licensing options to choose from to replace the deprecated tag. Dana boomer (talk) 00:13, 26 February 2009 (UTC)

I see, thanks. Fixed.--76.167.77.165 (talk) 01:39, 26 February 2009 (UTC)

• The first two images in the gallery in the Some important or well known results section need descriptions added to their image pages.

Fixed.--76.167.77.165 (talk) 22:14, 25 February 2009 (UTC)

• The formatting of the image gallery in the Applications section needs to be tweaked - the last image falls off the page.

Changed formatting. This will of course depend on your browser and screen.--76.167.77.165 (talk) 22:14, 25 February 2009 (UTC)

Once these issues are taken care of and a full copyedit is completed, please feel free to renominate this article at GAN. Please let me know if you have any questions or comments. Dana boomer (talk) 18:43, 24 February 2009 (UTC)

Thanks for the comments! Some of these I'll fix, others I'll leave to other people.--76.167.77.165 (talk) 22:06, 25 February 2009 (UTC)

Thanks, Dana boomer, for the helpful comments on the article. I think most of them are now pretty much taken care of, with the possible exception of references (not sure if they're sufficient now), and the definite exception of the choppiness, short paragraphs and short sections. I assume the latter was mostly referring to the section on applications, and I think that's a symptom of the fact that the application section is thin, and lacks any kind of narrative thread, transitions between topics, etc. That's not something that can be taken care of with a quick fix.--76.167.77.165 (talk) 07:21, 27 February 2009 (UTC)

Nomination of Portal:Geometry for deletion

A discussion is taking place as to whether Portal:Geometry is suitable for inclusion in Wikipedia according to Wikipedia's policies and guidelines or whether it should be deleted.

The page will be discussed at Wikipedia:Miscellany for deletion/Portal:Geometry until a consensus is reached, and anyone is welcome to contribute to the discussion. The nomination will explain the policies and guidelines which are of concern. The discussion focuses on high-quality evidence and our policies and guidelines.

Users may edit the page during the discussion, including to improve the page to address concerns raised in the discussion. However, do not remove the deletion notice from the top of the page. North America¹⁰⁰⁰ 23:26, 2 June 2019 (UTC)

Parallel postulate

At the time I write this, a section titled "Parallel postulate" includes the following sentence:

The "at most" clause is all that is needed since it can be proved from the remaining axioms that at least one parallel line exists.

So apparently spherical geometry is just a lie?!

Find such a parallel to the original line, in spherical geometry, and I will give you one of my lungs.

Why is such errant, provable nonsense in an encyclopedia? One might think that mathematics would be a more reliable subject than most for Wikipedia to cover, given that when it is wrong, we can prove it wrong. Yet reality appears to go the opposite way. Whatever can't get past a mathematician goes onto Wikipedia instead.

Even if it were correct, it would be impossible to learn mathematics from this source, because when page A links to B links to C links to A again, one must read A, B & C repeatedly just in order to get the gist of A. When it is actually wrong, on top of that, it is worse than useless.

Shut down Portal:Geometry, they say? Shut down maths on Wikipedia! Wrong is wrong and you can't fix it. Please, let it die. — Preceding unsigned comment added by 78.147.17.127 (talk) 22:29, 22 August 2019 (UTC)

Perhaps you should pay a little more attention to what is written. It is clearly stated that the parallel postulate is limited to a plane, as in "In a plane, ...". Spherical geometry is not a plane geometry, so your tirade above is quite misplaced. --Bill Cherowitzo (talk) 19:53, 23 August 2019 (UTC)

Section "Constructive approaches and pedagogy"

I have removed this section, which is written like an essay, and is an WP:original synthesis of WP:fringe theories. For example the author uses "axiomatic proof" for what everybody calls a proof and "Analytic proof" for something that is related to experimentation, and is definitely not a proof, as being "non-deductive". This is the most visible error of this section, but almost every sentence contains an historical error or an opinion that is not shared by the main stream of mathematics. D.Lazard (talk) 16:05, 10 August 2020 (UTC)

Where are the Axioms?

Some people say that Euclid's book don't contain axioms; I have no reason to argue that, not knowing Ancient Greek. But we are in 21st century, and more than one set of axioms of Euclidean Geometry is available, and I am sure must be either listed or refered. Any Mathematicians present here? I could write a section describing an axiomatic Euclidean Geometry, as it is what people expect from a geometry theory. Using a set-theoretical model of geometry is not enough for describing a theory. First, I hope at least some people know that there's more than one set theory; second, we are talking here about a theory, not about models, right?

I'd love to hear your opinion. Vlad Patryshev (talk) 15:29, 14 May 2022 (UTC)

The article mentions Playfair's axiom, perhaps you could develop that. You can also expand the logical basis section Lbertolotti (talk) 23:16, 9 June 2022 (UTC)

Some of the best known axiomatic formulations of Euclidean geometry are listed in section § Axiomatic formulations. Sure that this section should be made more visible and could be improved, but there is no reason for rewriting it from scratch.

You wrote "I could write a section describing an axiomatic Euclidean Geometry". As you do not say which existing axiomatisation you have in mind, I suppose that this would be your own axiomatization. This would be WP:OR, and, as such, would be strictly forbidden in Wikipedia. D.Lazard (talk) 08:58, 10 June 2022 (UTC)

Euclid's Geometry

What are postulates ? 103.170.68.3 (talk) 14:33, 29 June 2022 (UTC)

Follow the link: postulate. D.Lazard (talk) 15:27, 29 June 2022 (UTC)