Talk:Cross section (geometry)

Latest comment: 1 year ago by Mucketymuck in topic This article is confused about the definition

Simplify! edit

We need a much-simpler explanation of what a cross-section is, one with lots of pictures and no integrals! And no-no double integrals!
We need an description and and explantation of what a cross-section that is understandable by the General Reader.
If we take a cylinder and cut it with a plane parallel to its axis, what do we get? A circle, of course. Show people! If we cut the cylinder with a plane at some other angle, what do we get? Well, some kind of elliptical thing. Show it!
If we cut a rectangular prism with a plane, what do we get? Well, usually a rectangle.
If we cut and infinite cone with a plane, what do we get? Well, one of the conic sections, or course. Not everyone knows this. 98.67.111.148 (talk) 02:31, 26 July 2010 (UTC)Reply

Hmm,
 
Pictures like this?
187.107.7.64 (talk) 04:16, 26 August 2011 (UTC)Reply

This article is confused about the definition edit

It is not surprising that there are no references for this article since it gets (at least from the mathematical point of view) so much wrong. Not enough attention is being paid to the dimensions of the objects involved. Mathematically the term is applied, almost exclusively, to three-dimensional objects and the intersection of such with a plane is in general a two-dimensional object lying in that plane. This article confuses these two-dimensional objects with their boundaries. Thus, the cross-section of a circular cylinder perpendicular to the axis of the cylinder is a disk, not a circle (which is the boundary of that disk). Some of this confusion is probably due to the long standing abuse of notation found in elementary geometry where, for example, a circle could mean either a disk or the boundary of that disk depending on the context. This reliance on context is of course unacceptable in modern mathematics, so we need to be more careful with our descriptions and use the proper terms. Reliable references would get these distinctions clearly stated.--Bill Cherowitzo (talk) 17:52, 3 August 2017 (UTC)Reply

Good points, and I'll add that "non-empty" seems superfluous to this description, as solid bodies are ipso facto not empty. (However, cross-sections in practical use, as in engineering, will often use outlines to represent areas conjoined by material behind the section view, as in this page's top image, showing, on the left, a through-hole in a compression seal. Such cross-sections effectively represent pictures of objects with cutaway areas, the cutaway being accomplished with a plane parallel to the frontal view. In photographic cross-sections, the "plane" may have been, say, a saw.) Mucketymuck (talk) 04:10, 14 August 2022 (UTC)Reply

Proposal: move article to "Cross-section (geometry)" edit

"Cross-section" (with a hyphen) seems to match more common spelling in the broader community (e.g. [1] versus [2]), and also within the present WP article. The title should reflect that.
—DIV (137.111.13.4 (talk) 02:32, 16 April 2021 (UTC))Reply

"Tvärsnitt" listed at Redirects for discussion edit

  An editor has identified a potential problem with the redirect Tvärsnitt and has thus listed it for discussion. This discussion will occur at Wikipedia:Redirects for discussion/Log/2022 February 13#Tvärsnitt until a consensus is reached, and readers of this page are welcome to contribute to the discussion. ~~~~
User:1234qwer1234qwer4 (talk)
02:42, 13 February 2022 (UTC)Reply