Talk:Langley's Adventitious Angles

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The drawing must be wrong because the large triangle consists of angle B =80+20= 100degrees and angle C=80+30=110degrees and angle A=20degrees. Together these becomes 100+110+20= 230degrees inside the large triangle. That is not possible. All triangles have only 180degrees Please fix the article. Thank you. 193.71.60.110 (talk) 18:06, 8 December 2016 (UTC)[reply]

You are misinterpreting the drawing. B=80, not 80+20 (there is a 20 degree wedge inside it that does not add to it. Similarly C=80, not 80+30. —David Eppstein (talk) 18:50, 8 December 2016 (UTC)[reply]

The user, and myself, are misinterpreting the drawing because it is badly drawn. Nesting angles in this way is unclear and should be avoided without good reason. Calum (talk) 13:37, 9 May 2020 (UTC)[reply]

The statement of the problem involves angles that nest. So illustrating the problem as stated requires drawing nested angles. —David Eppstein (talk) 16:06, 9 May 2020 (UTC)[reply]

Then a better diagram is needed, or a restatement of the problem that does not require such a bad illustration. The triangle is isosceles; it is sufficient to state that angle A is 20 degrees. Calum (talk) 23:49, 19 March 2021 (UTC)[reply]

Generalization

Must contain generalized solution. Add it, please!--Nashev (talk) 19:29, 18 October 2017 (UTC)[reply]

Degrees

This is re. the misleading statement that "the sides are all rational (when measured in degrees)", which I addressed, only to be reversed, then tagged, only to have the tag deleted by two different editors -- one of whom admits that the statement is inaccurate!

Quadrangles aren't adventitious because they're measured in degrees. Come on, people, this is elementary, and it's irresponsible for us to imply that they are. Most people reading this article will understand that we don't actually mean what we say, and correct it in their heads. But you never know when someone is reading at the limit of their comprehension, and will be confused by inaccurate statements like this. — kwami (talk) 01:58, 8 July 2020 (UTC)[reply]

Do you agree that the set of angles that have rational degree measure is the same as the set of angles that have rational gradient measure? —JBL (talk) 02:05, 8 July 2020 (UTC)[reply]

If I were writing for mathematicians I'd write that the angle should be a rational multiple of

2\pi

, but per WP:TECHNICAL we should use the more accessible unit here. Which is not gradians. —David Eppstein (talk) 04:17, 8 July 2020 (UTC)[reply]

Ditto. Also, for anyone watching, User talk:David Eppstein#Warning is the main locus of discussion for some reason. --JBL (talk) 16:40, 8 July 2020 (UTC)[reply]

David, it's not about using the more accessible unit. It's about implying that the choice of unit defines whether or not a quadrangle is adventitious. If you don't like my wording, fine. Surely you can come up with wording of your own. And if (I'm not trying to be insulting here, merely making a point) you're not smart enough to explain this in your own words, what makes you think our readers will be smart enough to understand it without a proper explanation? — kwami (talk) 20:28, 8 July 2020 (UTC)[reply]

(The discussion should be here.) Response from David's page: I may very well not be intelligent or well-informed enough to come up with the proper wording, but that's rather beside the point. If the editors of the article, who are well-informed enough, are also not able to come up with a correct description, I don't see how we can expect uninformed readers to be able to understand an incorrect description. JBL, I would expect calculus students to understand "rational fraction of a circle", but if they don't, that just proves my point. But a footnote would of course be fine. — kwami (talk) 20:38, 8 July 2020 (UTC)[reply]

There is no "incorrect description" in the current article. —David Eppstein (talk) 20:40, 8 July 2020 (UTC)[reply]

There is a claim with an incorrect implication, that a fraction might need to be measured in degrees to determine whether a quadrangle is adventitious. It's obvious you understand this, since you admitted as much in your edit summary.

Truly, I cannot understand why you would obstinately oppose attempts to fix a problem with the article. Are you not able to accurately explain the situation? Can't you just ask JBL or another editor to come up with appropriate wording? — kwami (talk) 20:45, 8 July 2020 (UTC)[reply]

I continue not to see a problem to be fixed. There is no implication that only degrees will work. The angle needs to be measured in a unit system for which the whole circle is a rational number in order for it to be a rational number itself. It doesn't really matter for correctness of this sentence whether this unit system is degrees, gradians, multiples of a whole circle, or whatever. But it does matter for accessibility. The easiest, clearest, and most accessible way to express the requirement on the angles is to say that it is a rational number of degrees. Your original addition of gradians just confuses the issue without adding any value. —David Eppstein (talk) 20:54, 8 July 2020 (UTC)[reply]

Okay, my original fix was suboptimal. I'm not fighting to keep it. But where you say, The angle needs to be measured in a unit system for which the whole circle is a rational number in order for it to be a rational number itself -- anyone reading at this level should understand that. Therefore the comment about 'degrees' shouldn't be needed. But the people who *do* need to have it explained to them are not likely to get the point you just made if all you do is say "if measured in degrees". In attempting to make the article more accessible, you're potentially misleading the very people who need it to be more accessible.

How about we add your wording as a footnote, as JBL suggested? — kwami (talk) 21:33, 8 July 2020 (UTC)[reply]

Can't we just use something like "where each angle is a rational angle (a rational number of degrees or a rational multiple of pi radians)". Integer triangle#Integer triangles with three rational angles has something similar. --Salix alba (talk): 22:02, 8 July 2020 (UTC)[reply]

Yeah, I'd be happy with that too. I suppose it depends on whether you prefer footnotes or parentheses when reading. I love footnotes, some people hate them. As for your proposed change in wording, I have no strong opinion. Those of you who teach math should have a better idea of which wording would be more intelligible to the average reader. — kwami (talk) 08:18, 9 July 2020 (UTC)[reply]