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I think that the volume of this section is not correct. Please check Wolfram Research, Inc
http://mathworld.wolfram.com/SquarePyramid.html
for correct information. -- Kibria100 13:05, 20 June 2006 (UTC)
I removed this:
If the base is 756 ft and the slant-height is 719 ft, then the height is 612 ft; 719:612 is nowhere near the golden ratio. — Tamfang ( talk) 21:24, 6 April 2009 (UTC)
It may be worth mentioning in the "Other square pyramids" section, the pyramid (with apex above base centre) which has a height exactly half of the base length; this is the type of pyramid yielded by slicing a cube into six identical pyramids, and hence it is capable of entirely filling a 3D space without leaving any gaps, and without the help of any other polyhedron.
Also, by sticking six such pyramids to the faces of a cube, the result is a rhombic dodecahedron, and this could be mentioned in the "Related polyhedra and honeycombs" section. Certainly that section should be clarified a bit, regarding the tetrakis hexahedron; it should be mentioned that by "short" is meant a pyramid the height of which is less than half of the length of the base.
If citations can be found, these would be worthy additions. — 2A02:C7D:419:2500:207F:B0B3:C1A7:E60B ( talk) 09:17, 3 June 2017 (UTC)
@Administrator David Eppstein: Sorry for bothering you with an infobox again... But the infobox of the Square pyramid article should treat only the equilateral square pyramid, shouldn't it? In advance, thank you for your answer! -- JavBol ( talk) 20:35, 10 October 2021 (UTC)
GA toolbox |
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Reviewing |
Reviewer: David Eppstein ( talk · contribs) 18:20, 2 November 2023 (UTC)
At a first glance, this article looks in pretty good shape, much better than most of our polyhedra articles, with good care to distinguish the equilateral, right, and general cases, and refreshingly free of pyramidology. I think it is missing some topics, though ( WP:GACR 3a), I found one serious mistake, and I have some other more minor comments below.
Lead: "the Egyptian pyramid": there is more than one. Why singular when the linked article is plural? (GACR 1a) In the infobox, the claim that this polyhedron is self-dual (clearly true, as for all pyramids) is unsourced (GACR 2c) and is not discussed in the text of the article (GACR 1b,3a). The pyramid net is also unsourced and undiscussed. And the vertex configuration is sourced, but undiscussed and unexplained; the only way to find out what it means is to follow the link. In these cases, I think if there is a source in the body, it doesn't need the footnote to be repeated in the infobox.
Properties/Right and equilateral square pyramid: "Congruent" is a link to a disambiguation page (GACR 1a). In the second paragraph, the angles are sourced to Uehara, but I don't see them there (GACR 2c). Maybe Uehara was intended only to source the J1 numbering? I think the angles are in the Johnson source. In the third paragraph, Johnson sources the specific symmetry group of the pyramid, but I don't see where it sources the part in the first sentence about this being an example of a more general class of pyramidal symmetries (GACR 2c)
Properties/Surface area and volume: "The surface area A of a square pyramid can be expressed as": this formula is only for right square pyramids.
Applications, first paragraph: I wonder whether we should separate out the architectural applications from the history of volume calculations, with the calculation history possibly in a different section as it is not really about applications? According to Babylonian mathematics the Babylonians also tried to calculate volumes of pyramids but used an incorrect formula, and according to doi: 10.1016/0315-0860(79)90076-4 the ancient Chinese (much later) did so as well (GACR 3a). And while we mention Egyptian pyramids there is no mention of Mesoamerican pyramids.
Applications, first image: "The shape of an Egyptian pyramid is an equilateral square pyramid": WRONG! It is a right pyramid, and the exact shape is a matter of significant debate (see pyramidology), but it is definitely not equilateral. All of the "explanations" give it a slant height of roughly , but the mathematical ones vary as to whether this comes from , , , etc. (The removal of the outer surface of the pyramid makes it difficult to tell this experimentally, but a comparison with what the Egyptians wrote about their mathematics and their other architecture makes the integer ratio explanations more likely than the others.) An equilateral pyramid would have a slant height around 0.866, quite a bit higher and not consistent with the measurements (GACR 6b). For a non-cranky and reliable discussion of this see Herz-Fischler, Roger (2000). The Shape of the Great Pyramid, an entire book reviewing many different theories for the shape of the pyramids.
Applications, stereochemistry: what is the relation between this molecular geometry and the shape described in this article, beyond their similar names? (GACR 3b)
Applications, augmentation: do you really want to consider the regular octahedron to be an augmentation? If so it would have to be an augmentation of a square dihedron, no? Re "Some of the other Johnson solids ... these are": please fix the comma splice (GACR 1a).
See also: Can Square pyramidal number be discussed in the main article text rather than relegated to a see-also link (GACR 3a)? Maybe we could add Pyramidology as a see-also link instead (or mention it briefly in the context of the Egyptian pyramids).
References: Spot-checking found most content properly referenced (GACR 2b) and most references good for what they are referencing (GACR 2c) with a few exceptions noted above. Neither those checks nor Earwig found any significant copying (GACR 2d). All references appear to be reliable publications, consistently formatted in Citation Style 1 (GACR 2a).
External links: Within WP:EL rules, but the relevance of the wheel graph link is unclear. I think the topic is relevant, but should be explained in the article text (GACR 3a), and that with a proper explanation and wikilink, the external link would become unnecessary.
Neutrality (GACR 4) and stability (GACR 5): no issues. Media licensing and captioning (GACR 6): only one issue, noted above.
— David Eppstein ( talk) 01:46, 3 November 2023 (UTC)
@ Dedhert.Jr: Most of the changes look like improvements but there are some new grammar issues.
Lead: "with examples being Egyptian pyramids, along with the background of mensuration": the background of mensuration is not an example of architecture.
Surface area and volume: The choice to put the history of the formulas here is ok. But "The Babylonian mathematicians also found its volume, but stated that the incorrect formula is the half product of the height and the sum of quadrilateral bases.[17]": confusing grammar. There was some other incorrect formula and they stated what it was?
Applications: "However, modern scholars opposed this because it would not be inconsistent with Egyptian mathematics during construction, along with the fact that they did not know the utilization of the golden ratio in their theory of architecture and proportion": more confused grammar. "Not be inconsistent" is a double negative, for one thing, and the grammar of the two supposed reasons for scholars to disagree with this (not really oppose it) is not parallel.
— David Eppstein ( talk) 07:39, 8 November 2023 (UTC)
Ok, the article appears to have mostly stabilized. I made some minor copyedits to some text that still felt awkward to me, but other than that I think everything from this review was already addressed. I don't see anything important missing (for instance, there are too many modern pyramids for it to be a good idea to add many others). Passing for GA. — David Eppstein ( talk) 07:17, 20 November 2023 (UTC)
@ Dedhert.Jr: In response to your edit summary, I'd support a full switch to {{ sfn}} citations. I was going to go through and do some cleanup with the references anyways, so I might just do both at the same time if you're alright with that. — TechnoSquirrel69 ( sigh) 19:47, 20 November 2023 (UTC)
The result was: promoted by
AirshipJungleman29
talk
01:04, 14 January 2024 (UTC)
Improved to Good Article status by Dedhert.Jr ( talk). Self-nominated at 01:07, 21 November 2023 (UTC). Post-promotion hook changes for this nom will be logged at Template talk:Did you know nominations/Square pyramid; consider watching this nomination, if it is successful, until the hook appears on the Main Page.
@ David Eppstein. I'm considering expanding the properties section that includes the height, surface area, and volume of an equilateral square pyramid. Its height can be expressed as , but the source I have found source I have found explains the case of the unit edge. Does it count as WP:CALC if I multiply that height with random edge length ? An alternative source is from Spanish language, but I'm skeptical whether reliable or not. Dedhert.Jr ( talk) 11:51, 31 January 2024 (UTC)
![]() | Square pyramid has been listed as one of the Mathematics good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it. | |||||||||||||||||||||
|
![]() | This article is rated GA-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||||||||
|
![]() | The following references may be useful when improving this article in the future:
|
I think that the volume of this section is not correct. Please check Wolfram Research, Inc
http://mathworld.wolfram.com/SquarePyramid.html
for correct information. -- Kibria100 13:05, 20 June 2006 (UTC)
I removed this:
If the base is 756 ft and the slant-height is 719 ft, then the height is 612 ft; 719:612 is nowhere near the golden ratio. — Tamfang ( talk) 21:24, 6 April 2009 (UTC)
It may be worth mentioning in the "Other square pyramids" section, the pyramid (with apex above base centre) which has a height exactly half of the base length; this is the type of pyramid yielded by slicing a cube into six identical pyramids, and hence it is capable of entirely filling a 3D space without leaving any gaps, and without the help of any other polyhedron.
Also, by sticking six such pyramids to the faces of a cube, the result is a rhombic dodecahedron, and this could be mentioned in the "Related polyhedra and honeycombs" section. Certainly that section should be clarified a bit, regarding the tetrakis hexahedron; it should be mentioned that by "short" is meant a pyramid the height of which is less than half of the length of the base.
If citations can be found, these would be worthy additions. — 2A02:C7D:419:2500:207F:B0B3:C1A7:E60B ( talk) 09:17, 3 June 2017 (UTC)
@Administrator David Eppstein: Sorry for bothering you with an infobox again... But the infobox of the Square pyramid article should treat only the equilateral square pyramid, shouldn't it? In advance, thank you for your answer! -- JavBol ( talk) 20:35, 10 October 2021 (UTC)
GA toolbox |
---|
Reviewing |
Reviewer: David Eppstein ( talk · contribs) 18:20, 2 November 2023 (UTC)
At a first glance, this article looks in pretty good shape, much better than most of our polyhedra articles, with good care to distinguish the equilateral, right, and general cases, and refreshingly free of pyramidology. I think it is missing some topics, though ( WP:GACR 3a), I found one serious mistake, and I have some other more minor comments below.
Lead: "the Egyptian pyramid": there is more than one. Why singular when the linked article is plural? (GACR 1a) In the infobox, the claim that this polyhedron is self-dual (clearly true, as for all pyramids) is unsourced (GACR 2c) and is not discussed in the text of the article (GACR 1b,3a). The pyramid net is also unsourced and undiscussed. And the vertex configuration is sourced, but undiscussed and unexplained; the only way to find out what it means is to follow the link. In these cases, I think if there is a source in the body, it doesn't need the footnote to be repeated in the infobox.
Properties/Right and equilateral square pyramid: "Congruent" is a link to a disambiguation page (GACR 1a). In the second paragraph, the angles are sourced to Uehara, but I don't see them there (GACR 2c). Maybe Uehara was intended only to source the J1 numbering? I think the angles are in the Johnson source. In the third paragraph, Johnson sources the specific symmetry group of the pyramid, but I don't see where it sources the part in the first sentence about this being an example of a more general class of pyramidal symmetries (GACR 2c)
Properties/Surface area and volume: "The surface area A of a square pyramid can be expressed as": this formula is only for right square pyramids.
Applications, first paragraph: I wonder whether we should separate out the architectural applications from the history of volume calculations, with the calculation history possibly in a different section as it is not really about applications? According to Babylonian mathematics the Babylonians also tried to calculate volumes of pyramids but used an incorrect formula, and according to doi: 10.1016/0315-0860(79)90076-4 the ancient Chinese (much later) did so as well (GACR 3a). And while we mention Egyptian pyramids there is no mention of Mesoamerican pyramids.
Applications, first image: "The shape of an Egyptian pyramid is an equilateral square pyramid": WRONG! It is a right pyramid, and the exact shape is a matter of significant debate (see pyramidology), but it is definitely not equilateral. All of the "explanations" give it a slant height of roughly , but the mathematical ones vary as to whether this comes from , , , etc. (The removal of the outer surface of the pyramid makes it difficult to tell this experimentally, but a comparison with what the Egyptians wrote about their mathematics and their other architecture makes the integer ratio explanations more likely than the others.) An equilateral pyramid would have a slant height around 0.866, quite a bit higher and not consistent with the measurements (GACR 6b). For a non-cranky and reliable discussion of this see Herz-Fischler, Roger (2000). The Shape of the Great Pyramid, an entire book reviewing many different theories for the shape of the pyramids.
Applications, stereochemistry: what is the relation between this molecular geometry and the shape described in this article, beyond their similar names? (GACR 3b)
Applications, augmentation: do you really want to consider the regular octahedron to be an augmentation? If so it would have to be an augmentation of a square dihedron, no? Re "Some of the other Johnson solids ... these are": please fix the comma splice (GACR 1a).
See also: Can Square pyramidal number be discussed in the main article text rather than relegated to a see-also link (GACR 3a)? Maybe we could add Pyramidology as a see-also link instead (or mention it briefly in the context of the Egyptian pyramids).
References: Spot-checking found most content properly referenced (GACR 2b) and most references good for what they are referencing (GACR 2c) with a few exceptions noted above. Neither those checks nor Earwig found any significant copying (GACR 2d). All references appear to be reliable publications, consistently formatted in Citation Style 1 (GACR 2a).
External links: Within WP:EL rules, but the relevance of the wheel graph link is unclear. I think the topic is relevant, but should be explained in the article text (GACR 3a), and that with a proper explanation and wikilink, the external link would become unnecessary.
Neutrality (GACR 4) and stability (GACR 5): no issues. Media licensing and captioning (GACR 6): only one issue, noted above.
— David Eppstein ( talk) 01:46, 3 November 2023 (UTC)
@ Dedhert.Jr: Most of the changes look like improvements but there are some new grammar issues.
Lead: "with examples being Egyptian pyramids, along with the background of mensuration": the background of mensuration is not an example of architecture.
Surface area and volume: The choice to put the history of the formulas here is ok. But "The Babylonian mathematicians also found its volume, but stated that the incorrect formula is the half product of the height and the sum of quadrilateral bases.[17]": confusing grammar. There was some other incorrect formula and they stated what it was?
Applications: "However, modern scholars opposed this because it would not be inconsistent with Egyptian mathematics during construction, along with the fact that they did not know the utilization of the golden ratio in their theory of architecture and proportion": more confused grammar. "Not be inconsistent" is a double negative, for one thing, and the grammar of the two supposed reasons for scholars to disagree with this (not really oppose it) is not parallel.
— David Eppstein ( talk) 07:39, 8 November 2023 (UTC)
Ok, the article appears to have mostly stabilized. I made some minor copyedits to some text that still felt awkward to me, but other than that I think everything from this review was already addressed. I don't see anything important missing (for instance, there are too many modern pyramids for it to be a good idea to add many others). Passing for GA. — David Eppstein ( talk) 07:17, 20 November 2023 (UTC)
@ Dedhert.Jr: In response to your edit summary, I'd support a full switch to {{ sfn}} citations. I was going to go through and do some cleanup with the references anyways, so I might just do both at the same time if you're alright with that. — TechnoSquirrel69 ( sigh) 19:47, 20 November 2023 (UTC)
The result was: promoted by
AirshipJungleman29
talk
01:04, 14 January 2024 (UTC)
Improved to Good Article status by Dedhert.Jr ( talk). Self-nominated at 01:07, 21 November 2023 (UTC). Post-promotion hook changes for this nom will be logged at Template talk:Did you know nominations/Square pyramid; consider watching this nomination, if it is successful, until the hook appears on the Main Page.
@ David Eppstein. I'm considering expanding the properties section that includes the height, surface area, and volume of an equilateral square pyramid. Its height can be expressed as , but the source I have found source I have found explains the case of the unit edge. Does it count as WP:CALC if I multiply that height with random edge length ? An alternative source is from Spanish language, but I'm skeptical whether reliable or not. Dedhert.Jr ( talk) 11:51, 31 January 2024 (UTC)