Talk:Intercept theorem

	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
Low	This article has been rated as Low-priority on the project's priority scale.

Error in calculating the pyramid's height?

The article says:

C=2m+63m+{\frac {230m}{2}}=180m

But why is the addition of "2m" needed? It seems an error. —Preceding unsigned comment added by 93.172.84.58 (talk) 07:34, 24 August 2009 (UTC)[reply]

You are correct, the 2m are actually included in the 63m shadow of the pyramid. I'll fix it.--Kmhkmh (talk) 08:09, 24 August 2009 (UTC)[reply]

Thanks. One more thing: I think "shadow of the pole (A)" should be changed to "shadow of the pole (B)".

About calculating the pyramid's height

It might be worth explaining that the two triangles (the pyramid's and the pole's) are similar only because the sun is very far and is thus practically "at inifinity". This makes the angle at the top of the triangles congruent. The picture is misleading because it shows the sun very low and thus it's not clear why the hypotenuse of the pole's triangle has the same slope as that of the pyramid's triganle. —Preceding unsigned comment added by 93.173.110.65 (talk) 01:11, 26 August 2009 (UTC)[reply]

Proof

Is it only me or the proof given in the article is way too complicated? I suggest this one:

That's exactly what the proof does, that picture is just a rotated version of the one in the proof.--Kmhkmh (talk) 15:36, 18 February 2011 (UTC)[reply]

Haha, sorry, I didn't know that notation of $|\triangle CDA|=|\triangle CBA|$ , so I stopped reading the proof and did not pay attention on the figure. Then I went searching for another proof, my mistake, hehe. Thanks for the attention.

What is claim 4?

It says "Claim 4 can be shown by applying the intercept theorem for two lines." But what can be shown? What is claim 4? — Preceding unsigned comment added by 27.255.243.2 (talk) 09:52, 15 July 2015 (UTC)[reply]

claim 4 is stated in the formulation section.--Kmhkmh (talk) 01:41, 1 October 2015 (UTC)[reply]

temporary removal

I temporarly removed the following section, because for one it was unsourced but more importantly it lacks a proper explanation of the complex construction and its goal. I assume this is meant as a practical example for role the intercept theorem plays for the set of constructable numbers (explained further up in the article). However it might be be better choice to to construct a simpler 2 digits number to illustrate mechanics rather than going for a pi approximation. But in any to make such a picture a useful addition to the article, it requires some more detailed explanatory description.--Kmhkmh (talk) 01:39, 1 October 2015 (UTC)[reply]

The construction of a decimal number

A practical example of the intercept theorem in combination with number line. (Situation following revision October 15, 2015)

View

Animation

literature & links

https://www.youtube.com/watch?v=cACn06wXkYY

Thales' or Thales's

@Wcherowi: the other article is titled Thales's theorem, and there's also MOS:POSS. wumbolo ^^^ 21:40, 20 January 2019 (UTC)[reply]

Well to my knowledge both versions are correct and somewhat common in English. However if WP has a generally accepted house rule like MOS:POSS, that favours one version the case seems clear. Personally however I gave up on following the current state of the extensive manual of style (or caring much about it).--Kmhkmh (talk) 22:02, 20 January 2019 (UTC)[reply]

Wumbolo We just been through a long discussion at Stokes' theorem concerning the recent change to MOS:POSS and my reading of the result favored revisiting that change. I would suggest not making a change in the use of 's until that has been worked out. --Bill Cherowitzo (talk) 22:07, 20 January 2019 (UTC)[reply]

Out of curiousity. Do you have a link to the ongoing dispute/recent change with regard to s' vs s's issue--Kmhkmh (talk) 22:54, 20 January 2019 (UTC)[reply]

No I don't. The final consensus at Talk:Stokes' theorem was to not move the title (that is, not apply the current MOS:POSS) and carried a recommendation to review MOS:POSS. This decision was also placed on the bottom of the MOS talk page, but I haven't seen any further discussion yet. --Bill Cherowitzo (talk) 05:20, 21 January 2019 (UTC)[reply]

side splitter theorem

Also known as side splitter theorem Huzaifa abedeen (talk) 13:52, 18 February 2021 (UTC)[reply]

Intercept theorem or Basic proportionality theorem

I think there is a misconception in the entire article about Intercept theorem. As far as I know Intercept theorem states that "If three or more parallel lines make equal intercepts on a given transversal, they will make equal intercepts on any other transversal."

Whereas Basic proportionality theorem (BPT) states that "If a line is drawn parallel to one side of a triangle intersecting the other two sides, then it divides the sides in the same ratio". In fact the Basic proportionality theorem can be used to prove Intercept theorem itself. Please suggest your opinion whether to move the article to BPT or not. Nishānt Omm (talk) 13:40, 2 May 2022 (UTC)[reply]

No, first of all the theorem as original stated is called intercept theorem (as can be among other by sources used in the article). The figure with three or more parallel lines is just variation of essentially the same statement und hence usually the same name is used for it.-Kmhkmh (talk) 19:15, 24 May 2022 (UTC)[reply]

proof of claim 1: angles

Angles SCB and SDA cannot be equal, the first is greater than 90 degrees, the second is less than 90 degrees. Unless the labels are wrong? 138.229.234.64 (talk) 19:54, 30 January 2023 (UTC)[reply]