Talk:Antiparallelogram

Antiparallelogram has been listed as one of the Mathematics good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.

Article milestones
Date	Process	Result
January 19, 2022	Good article nominee	Listed
A fact from this article appeared on Wikipedia's Main Page in the "Did you know?" column on February 14, 2022. The text of the entry was: Did you know ... that an antiparallelogram (example pictured) is a crossed quadrilateral with two pairs of equal-length edges?

Mathematics Low‑priority

	Mathematics portal This article is within the scope of WikiProject Mathematics, a collaborative effort to improve the coverage of mathematics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.MathematicsWikipedia:WikiProject MathematicsTemplate:WikiProject Mathematicsmathematics articles
Low	This article has been rated as Low-priority on the project's priority scale.

Polyhedra

	This article is within the scope of WikiProject Polyhedra, a collaborative effort to improve the coverage of polygons, polyhedra, and other polytopes on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.PolyhedraWikipedia:WikiProject PolyhedraTemplate:WikiProject PolyhedraPolyhedra articles
???	This article has not yet received a rating on the importance scale.

Translated part of this article[edit]

Wait, I translated a part of this article, some expert translator will translate from the article name that first appeared on any Wikipedias. A part of the article is translated, more will continue later. --Pumpie 19:44, 12 July 2006 (UTC)[reply]

Possible??[edit]

Is this figure possible?? Show me a picture. Georgia guy 00:15, 17 July 2006 (UTC)[reply]

Exact definition[edit]

The definition here states that "the two longest sides cross each other instead of being parallel". Why is there a requirement that the longest sides (instead of the two shorter sides) have to cross?

In all of the citations in the references section, the definitions found there have no mention of this. I think it should be removed.

--Mordomo (talk) 23:11, 16 December 2015 (UTC)[reply]

Nevermind. I see now that only the longest sides can cross. I've changed the article to make the introductory definition simpler based on the definitions found in the references, but added a sentence to say that it is the longest sides that cross. --Mordomo (talk) 10:10, 19 December 2015 (UTC)[reply]

GA Review[edit]

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

Reviewer: Elli (talk · contribs) 14:12, 10 January 2022 (UTC)[reply]

Initial comments[edit]

Article is in decent shape. Going to go section-by-section with the review here. Elli (talk | contribs) 14:12, 10 January 2022 (UTC)[reply]

Geometric properties[edit]

First paragraph is appropriately sourced.
The four midpoints of its sides lie on a line perpendicular to the axis of symmetry; that is, for this kind of quadrilateral, the Varignon parallelogram is a degenerate quadrilateral consisting of four collinear points. the second part of this sentence isn't in the source, but I guess can be reasonably inferred from the definition of a Varignon parallelogram. Would be better to have a reference here though.
Everything else in the second paragraph is fine.
Can't access the De Villiers or Demaine & O'Rourke references, but the paragraph is OK assuming those verify the content.

I think the De Villiers reference, based off of the title, might be usable for the second paragraph? Elli (talk | contribs) 14:40, 10 January 2022 (UTC)[reply]

- An online version of De Villiers can be found by searching for its title; I haven't linked it because I'm not entirely convinced that its not a pirated copy that would fail WP:ELNEVER. But as you say, he does discuss the degeneracy of the Varignon parallelogram, stating that it happens for crossed quads of signed area zero. So it does make sense to add that as a reference to the earlier line; I have done so. —David Eppstein (talk) 02:05, 14 January 2022 (UTC)[reply]
  - Great, looks good. Continuing (sorry with how long this took, I'm not the best at remembering when I do GA reviews) Elli (talk | contribs) 03:35, 19 January 2022 (UTC)[reply]

Applications[edit]

In polyhedra[edit]

Assuming good faith on the sources, no issues. Images are appropriate but I might also add the reference to the caption, since it doesn't seem like the captions of the second and third images are verified in the prose?

Four-bar linkages[edit]

Page numbers would be pretty useful for Abbott 2008. Not a huge issue though.
Most of the sources here aren't linked (which is fine); the ones I could check verified the content so I'm comfortable assuming good faith on the others.

Gear design[edit]

No issues here.

Celestial mechanics[edit]

No issues here.

Lead[edit]

Accurately summarizes the article. I might swap the second and third paragraphs to correspond with how the articles is ordered but that's not a big deal and I can also see the benefits to listing the applications first, too.

Overall[edit]

GA review (see here for what the criteria are, and here for what they are not)

It is reasonably well written.
a (prose, spelling, and grammar): b (MoS for lead, layout, word choice, fiction, and lists):
It is factually accurate and verifiable.
a (reference section): b (citations to reliable sources): c (OR): d (copyvio and plagiarism):
It is broad in its coverage.
a (major aspects): b (focused):
It follows the neutral point of view policy.
Fair representation without bias:
It is stable.
No edit wars, etc.:
It is illustrated by images and other media, where possible and appropriate.
a (images are tagged and non-free content have fair use rationales): b (appropriate use with suitable captions):
Illustrated with relevant, free images.
Overall:
Pass/Fail:
There's a few suggestions of improvements in this review but I don't find them sufficiently problematic to hold up passing the article. Elli (talk | contribs) 03:35, 19 January 2022 (UTC)[reply]

Did you know nomination[edit]

The following is an archived discussion of the DYK nomination of the article below. Please do not modify this page. Subsequent comments should be made on the appropriate discussion page (such as this nomination's talk page, the article's talk page or Wikipedia talk:Did you know), unless there is consensus to re-open the discussion at this page. No further edits should be made to this page.

The result was: promoted by SL93 (talk) 01:45, 8 February 2022 (UTC)[reply]

(

Comment or view
Article history

)

An antiparallelogram

... that an antiparallelogram (pictured) is a crossed quadrilateral with two pairs of equal-length edges? Source: Begalla & Perucca [1] "an antiparallelogram (namely a crossed quadrilateral such that the two opposite sides and the two crossing sides have equal length)"
- Reviewed: Template:Did you know nominations/Joseph Vallot

Improved to Good Article status by David Eppstein (talk). Self-nominated at 22:46, 19 January 2022 (UTC).[reply]

Freshly promoted GA, long enough, no policy issues. Hook is short enough and to the point. QPQ has been done. Image is fine and used in the article. Nothing to complain here, good to go! —Kusma (talk) 16:15, 21 January 2022 (UTC)[reply]
Forgot the tick, sorry! —Kusma (talk) 17:05, 21 January 2022 (UTC)[reply]