Talk:Octahedron

message: This article says there are 5 Andreini tessellations, but the article Andreini tessellation says there are 28. Which is correct? --Auximines 13:14, 21 Apr 2004 (UTC)
replies: text: Maybe someone meant to say that five (would you believe six?) of the 28 contain octahedra.  —Tamfang 06:53, 25 November 2006 (UTC)
thread_title:  Andreini Tessellations 

message: I replace stat table with template version, which uses tricky nested templates as a "database" which allows the same data to be reformatted into multiple locations and formats. See here for more details: User:Tomruen/polyhedron_db_testing
: Tom Ruen 00:53, 4 March 2006 (UTC)
thread_title:  New stat table 

message: i really need to know how i would get the formula that is given for the volume of the octahedron.... like.. the working out to get the formula...
PLEASE, THANKYOU
-Dave  —Preceding unsigned comment added by 58.169.29.65 (talk • contribs) 17:39, 9 October 2006
: Well, let's see.  Starting with the octahedron whose vertices are (0,0,±1) etc., consider the "first octant", that portion in which x,y,z are all positive.  That's a (skew) pyramid whose base is a right triangle.  A pyramid's volume is (height)×(area of base)/3; the base is half of a unit square, and the height is 1, so the pyramid's volume is 1/6.  There are eight such pyramids, so the total volume is 8/6 = 4/3.  But it's usual to express volume in terms of the edge length, and this octahedron has edge √2; so we divide 4/3 by the cube of √2 and get (√2)/3 for the volume of an octahedron of unit edge.  I didn't look at the answer while deriving this, so now I will — ah, good. ;)  —Tamfang 04:52, 11 October 2006 (UTC)
replies: text:  I ought perhaps to have mentioned that I looked it up in Regular Polytopes. —Tamfang (talk) 05:43, 6 February 2009 (UTC)

text: Yes, no, no. —Tamfang (talk) 01:38, 4 May 2010 (UTC)
thread_title:  volume 

message: I changed the hexagonal prism from 6 triangle to 6 squares.  To the best of my knowledge, that is how a hexagonal prism is constructed.  Change it back if I was in error.
Scott MacHardy 02:35, 23 October 2006 (UTC)
replies: text: Everyone makes mistakes!  —Tamfang 04:14, 28 October 2006 (UTC)
thread_title:  hexagonal prism 

message: The substance Alum is generally octahedral i beleive (at least, mine always is). Perhapse it should be mentioned somewhere?
71.28.13.158 03:35, 28 November 2006 (UTC)
thread_title:  Alum 

message: It occurs to me that the subgroups of Oh include Th as well as Td.  Is there a figure that we can associate with that subgroup?  —Tamfang 22:56, 25 April 2007 (UTC)
thread_title:  subgroups 

message: What does it mean "place notes at the vertex"?
205.155.71.58 (talk) 21:49, 31 July 2008 (UTC)
replies: text: It means that each vertex represents a note in the hexany scheme.  I'd take the section out. —Tamfang (talk) 07:38, 11 August 2008 (UTC)
thread_title:  octahedra in music 

message: From the article: "The octahedron's symmetry group is Oh, of order 48, the three dimensional hyperoctahedral group."
From Hyperoctahedral group: "In three dimensions, the hyperoctahedral group is known as the binary octahedral group."
But the Binary octahedral group has only one involution, while the symmetry group of the octahedron clearly has more than one.
There is something wrong here, but I don't know the terminology well enough to say where. Maproom (talk) 15:18, 8 September 2009 (UTC)
replies: text: Ok, this has been fixed, JackSchmidt has corrected the Hyperoctahedral group article. Maproom (talk) 22:21, 10 September 2009 (UTC)
thread_title: Symmetry group

message: The following Wikimedia Commons file used on this page has been nominated for deletion:
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Participate in the deletion discussion at the . —Community Tech bot (talk) 17:54, 18 May 2019 (UTC)
thread_title:  A Commons file used on this page has been nominated for deletion 

message: I intended to add a menu link to de:Oktaeder, but get an error "Site link dewiki:Oktaeder is already used by item Q12557050", which is []. Would anybody experienced fix this, pls? -- 185.69.244.210 (talk) 20:35, 10 January 2021 (UTC)
thread_title:  Link to German language