# Talk:Antiparallelogram

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)

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

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)

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)

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)


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


### Geometric properties
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)

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)
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)


### Applications
#### In polyhedra
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
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
No issues here.


#### Celestial mechanics
No issues here.


### Lead
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
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)