Pythagoras's theorem similar triangles proof.

[edit]

Voting period is over. Please don't add any new votes. Voting period ends on 19 Apr 2012 at 05:16:05 (UTC)

Original – Proof using similar triangles.
Reason
High technical standard and resolution, public domain, verifiable in article, complete file description. It adds value to article. It is a graphic so criteria 8 doesn't apply. I can't say anything about criteria 3.
Articles in which this image appears
Pythagorean theorem
FP category for this image
Wikipedia:Featured pictures/Diagrams, drawings, and maps/Diagrams
Creator
Gauravjuvekar

The figure there is at best described as "crude" with a simple right angled triangle ABC(B is the right angle) and a perpendicular BD onto AC(hypotenuse). The figure there is black and white with only the right angles marked(no other markings except vertices). The exact proof there is:
In \tri ABC, seg BD \perp hypotenuse AC ...(construction)


\ther \tri ABC ~ \tri ADB ...(similarity in right angled triangles)


\ther AB/AD=AC/AB ...(corresponding sides of similar triangles)


\ther AB^2=AC X AD ...(i)


Similarly, we have \tri ABC ~ \tri BDC


\ther BC/DC=AC/BC ...(corresponding sides of similar triangles)


\ther BC^2=AC X DC ...(ii)


\ther AB^2 + BC^2 =AC X AD + AC X DC ...[by adding (i) and (ii)]


=AC(AD+DC)


=AC X AC ...(A-D-C)


=AC^2


\ther AB^2 + BC^2=AC^2



I couldn't be bothered to use the math tags again so \tri means the triangle symbol(Delta), \ther means the therefore symbol(three dots) and X means the multiplication sign. Everything after ... are reasons for the corresponding statements.

I didn't originally reference it as the book is unreliable (IMO) with frequent errors. (eg:An image from Wikipedia is cited as htpp[sic]://en.wikipedia.org/wiki/pythagorean-themorem[sic] (pages 3, 4 and 5)[since when do Wikipedia articles have pages])I have several other reasons that don't belong here.


BTW I didn't understand what you meant by as if we're expected to validate it ourselves.--Gauravjuvekar (talk) 11:52, 10 April 2012 (UTC)[reply]

If you have a book which demonstrates that this image is correct and uses the proof - and is a reliable source - then add it. I would like to see one before I can support. Grandiose (me, talk, contribs) 18:50, 10 April 2012 (UTC)[reply]
I believe the nomination is correct. The image significantly adds to the article by illustrating the proof. The proof given is in response to my verifiability/sourcing comment, not part of the nomination. Grandiose (me, talk,contribs) 18:50, 10 April 2012 (UTC)[reply]
@Alvesgaspar--The proof is not with regard to this figure, it's according to the one given in the book. For it to make sense, just switch labels of vertex C and B and rename H as D--Gauravjuvekar (talk) 03:55, 11 April 2012 (UTC)[reply]
Support: does everything that is required of it that I can see under the criteria, being clear, informative and adding considerably to understanding the proof, which would frankly be unintelligible to most readers without. Now verifiable. Grandiose (me, talk, contribs) 06:50, 11 April 2012 (UTC)[reply]

Yes, the textbook is a source for the figure and the proof.(The figure is slightly different, the positions of B and C are switched and H is labeled D but that doesn't really matter much) I didn't understand what you meant by we use arrows around the "c", but not other letters. The arrows around c denote the length of c is AB.(Just as AC is b and BC is a, AB is c). Writing it without the arrows in the same line as d and e would be confusing. Lastly, I really don't know how to make it fit the article text. Could you please explain the part about the 'c' and the arrows around it in detail?--Gauravjuvekar (talk) 04:02, 12 April 2012 (UTC)[reply]

  • I don't understand "doesn't even illustrate well the proof in the article": it illustrates Pythagorean_theorem#Proof_using_similar_triangles very well in my opinion, and some sort of diagram there is vital to the reader. I get JJ's points but they appear to be in a useful discussion about them.
FPCR #1 requires a high technical standard, something widely assumed to not really apply to SVGs, and I don't see that any part of it is an issue here. #2 requires a high resolution, not applicable to an SVG. #3: "Is among Wikipedia's best work." ~ I don't think there's a better way of presenting this, if JJ's points are addressed. Otherwise #3 is appropriately covered by what I believe to be "diagrams and other illustrations are clear and informative." and "highly informative". #4 is clearly fulfilled, and I beleive as regards #5 that it is vital to a reader understanding the proof being given, unless they're very good at picturing it in their heads. Verifiability I believe is there, subject to any of JJ's concerns being fulfilled. Which criterion do you believe is not fulfilled? I'd hardly describe my approach as "more or less hollow". Grandiose (me, talk, contribs) 10:16, 14 April 2012 (UTC)[reply]
Could you please clarify which of the criteria requires a given picture to be "exceptional"? #3 is the closest but draws a comparison between the image and similar images, where this would do well. Grandiose (me, talk, contribs) 12:32, 14 April 2012 (UTC)[reply]
  • From the top of the FPC page: Featured pictures are images that add significantly to articles, either by illustrating article content particularly well, or being eye-catching to the point where users will want to read its accompanying article. Taking the adage that "a picture is worth a thousand words," the images featured on Wikipedia:Featured pictures should illustrate a Wikipedia article in such a way as to add significantly to that article, according to the featured picture criteria. -- Alvesgaspar (talk) 12:44, 14 April 2012 (UTC)[reply]
  • Please read the entire section in the article, it won't take long. The second paragraph uses the vertices to denote triangles. Hence they are needed(A, B, C and H). But it refers to the hypotenuse as "c" being divided into "d" and "e" at point "H" and the ratios below use the a, b, c, d, e forms(in math tags). Hence both forms are needed. Change the wording in the article and I will change/remove the markings in the image accordingly. I feel that you are confusing Commons and Wikipedia FPC. Commons FP require WOW factor so this image is unlikely to pass at Commons because it's "too simple". Wikipedia FPCs require EV which I feel is satisfied by this image and hence, this nomination is at Wikipedia.--Gauravjuvekar (talk) 15:04, 14 April 2012 (UTC)[reply]
I don't think just the colour on 'c' would suffice as floating the 'c' wouldn't be much effective. I think the arrow is very much needed.--Gauravjuvekar (talk) 11:38, 15 April 2012 (UTC)[reply]
  • Wiki (and most web pages) displays sans serif fonts for readability reasons only (might change with new high density pixels screens), but you are probably right when you mention the font should match the article's. Unfortunately for you the article has mix of both, since the formulas are rasterized from a typical LaTeX output. I would stuck to the serif version, but now it's only a matter of tastes. My "inconsistency" and "removing useless elements points" still stand. - Blieusong (talk) 18:49, 17 April 2012 (UTC)[reply]
  • LaTeX uses Computer Modern font (it's actually a family of font, and a default setup LaTeX uses the roman italic variant of it for mathematical formulas). It's free to use, and I think it's be easy to find version (true type?) you can use from your vector program (Inkscape it seems). This would make your diagram more consistent with the formulas for sure. - Blieusong (talk) 18:55, 17 April 2012 (UTC)[reply]

Not Promoted --Makeemlighter (talk) 21:57, 19 April 2012 (UTC)[reply]