# What do you call a three dimensional rectangle? **URL:** \ **Category:** Factual Questions\ **Created:** [February 22, 2006, 11:27pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700 "2006-02-22T23:27:03Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Northern\_Piper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/northern_piper/32/5304_2.png) [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)\ **Post date:** [February 23, 2006, 5:06am UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/21 "2006-02-23T05:06:19Z")
are you guys sure about that cuboid thing? sounds like a factoid to me. 😛 ---
**Author:** ![GorillaMan](https://avatars.discourse-cdn.com/v4/letter/g/50afbb/32.png) [@GorillaMan](https://boards.straightdope.com/u/GorillaMan)\ **Post date:** [February 23, 2006, 8:19am UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/22 "2006-02-23T08:19:00Z")
The perfect cite: [http://mathworld.wolfram.com/RectangularParallelepiped.html](http://mathworld.wolfram.com/RectangularParallelepiped.html) ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [February 23, 2006, 8:21am UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/23 "2006-02-23T08:21:10Z")
> [@Suburban Plankton](#): > > There is only one problem: it suggests a “cube”, which is absolutely not the case. I think the suggestion is a useful one; they are related solids, in fact a cube could be described as a _regular cuboid_. ---
**Author:** ![sturmhauke](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@sturmhauke](https://boards.straightdope.com/u/sturmhauke)\ **Post date:** [February 23, 2006, 8:49am UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/24 "2006-02-23T08:49:01Z")
Cuboid is perfectly acceptable, despite my never having heard it before. However, we do have toroids and sphereoids, which are the class of objects shaped roughly like toruses and spheres, respectively. ---
**Author:** ![KJ](https://avatars.discourse-cdn.com/v4/letter/k/b2d939/32.png) [@KJ](https://boards.straightdope.com/u/KJ)\ **Post date:** [February 23, 2006, 11:01am UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/25 "2006-02-23T11:01:30Z")
I was going to say “hexahedron,” but I’m pretty sure that refers to anything with the same topography as a cube, including shapes with weird angles. “Rectangular prism” is what I remember learning in grade school. ---
**Author:** ![N9IWP](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/n9iwp/32/3154_2.png) [@N9IWP](https://boards.straightdope.com/u/N9IWP)\ **Post date:** [February 23, 2006, 12:51pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/26 "2006-02-23T12:51:48Z")
One problem with **prism** is that prisms don’t have toi be “right”, that is, extruded and a 90 degree angle. Take a rectangle. Then extrude it at a 45 degree angle. To visualize this, here is the plane of the rectangle edge on: ----/---- This is still a prism. So to describe a box / block shape “right rectangular prism” is more accurate. (tho “right” can probably be implied in non matematical contexts) Brian ---
**Author:** ![Bytegeist](https://avatars.discourse-cdn.com/v4/letter/b/9dc877/32.png) [@Bytegeist](https://boards.straightdope.com/u/Bytegeist)\ **Post date:** [February 23, 2006, 2:49pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/27 "2006-02-23T14:49:33Z")
> [@KJ](#): > > I was going to say “hexahedron,” but I’m pretty sure that refers to anything with the same topography as a cube, including shapes with weird angles. True, but perhaps _regular hexahedron_ is another possibility for the solid’s name — making four now total. Or how about “limiting super ellipsoid”? I’m sure that term would catch on, if we all start using it. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [February 23, 2006, 3:20pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/28 "2006-02-23T15:20:21Z")
> [@Bytegeist](#): > > True, but perhaps _regular hexahedron_ is another possibility for the solid’s name — making four now total. Surely this could only describe a cube, not any kind of rectangular prism/cuboid? ---
**Author:** ![Bytegeist](https://avatars.discourse-cdn.com/v4/letter/b/9dc877/32.png) [@Bytegeist](https://boards.straightdope.com/u/Bytegeist)\ **Post date:** [February 23, 2006, 3:41pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/29 "2006-02-23T15:41:39Z")
> [@Mangetout](#): > > Surely this [“regular hexahedron”] could only describe a cube, not any kind of rectangular prism/cuboid? Ah, you’re right. Scratch that idea. ---
**Author:** ![Thudlow\_Boink](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thudlow_boink/32/320_2.png) [@Thudlow\_Boink](https://boards.straightdope.com/u/Thudlow_Boink)\ **Post date:** [February 23, 2006, 4:22pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/30 "2006-02-23T16:22:20Z")
Is there anything wrong with “rectangular solid”? “Rectangular parallelepiped,” though correct, is a hellacious mouthful to say, especially compared with nice simple words like “cube” or “sphere.” But as far as I know, there isn’t a single, simple word for it. In a context in which I had to refer to one repeatedly, like teaching a math class, I’d probably call it a “rectangular solid” or “rectangular box” the first couple of times and then refer to it as just a “box” thereafter. ---
**Author:** ![garygnu](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garygnu/32/2924_2.png) [@garygnu](https://boards.straightdope.com/u/garygnu)\ **Post date:** [February 23, 2006, 4:39pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/31 "2006-02-23T16:39:56Z")
I 've never heard anything but “rectangular solid” for a technical term, and I don’t see why “box” is wrong or inadequate colloquially. ---
**Author:** ![pretend\_my\_name\_is\_witty](https://avatars.discourse-cdn.com/v4/letter/p/b9e5f3/32.png) [@pretend\_my\_name\_is\_witty](https://boards.straightdope.com/u/pretend_my_name_is_witty)\ **Post date:** [February 23, 2006, 6:14pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/32 "2006-02-23T18:14:57Z")
This might be a Britishism, but whatever happened to the word **‘Oblong’** as a substitute for rectangle? Noel Fielding did a sketch on this, about how Oblong is a word that only five-year-olds and under can get away with saying. _Five year old_ “That’s an oblong” _Responsible adult_ “Er
no
I think you’ll find that’s a _rectangle_” ---
**Author:** ![Trunk](https://avatars.discourse-cdn.com/v4/letter/t/87869e/32.png) [@Trunk](https://boards.straightdope.com/u/Trunk)\ **Post date:** [February 23, 2006, 7:32pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/33 "2006-02-23T19:32:21Z")
Is calling that a 3D-Simplex inaccurate? I guess that would be like calling a triangle a 2D-Simplex, but 3D-Simplex was the first thing that popped into my mind. Or is a _3D Simplex_ more general than that? ---
**Author:** ![Cervaise](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cervaise/32/16693_2.png) [@Cervaise](https://boards.straightdope.com/u/Cervaise)\ **Post date:** [February 23, 2006, 7:36pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/34 "2006-02-23T19:36:41Z")
> [@garygnu](#): > > I 've never heard anything but “rectangular solid” for a technical term, and I don’t see why “box” is wrong or inadequate colloquially. I’m going to start asking people in the office to start thinking outside the rectangular solid. ---
**Author:** ![DarrenS](https://avatars.discourse-cdn.com/v4/letter/d/977dab/32.png) [@DarrenS](https://boards.straightdope.com/u/DarrenS)\ **Post date:** [February 23, 2006, 7:45pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/35 "2006-02-23T19:45:37Z")
> [@pretend my name is witty](#): > > This might be a Britishism, but whatever happened to the word **‘Oblong’** as a substitute for rectangle? [Wikipedia](http://en.wikipedia.org/wiki/Rectangles) 's take on this: > [@](#): > > The word oblong was once commonly used as an alternate name for a rectangle. In his translation of Euclid’s Elements, Sir Thomas Heath translates the Greek word Î”Ï„Î”ÏÎżÎŒÎ·ÎșΔς [hetero mekes – literally, “different lengths”] in Book One, Definition 22 as oblong. “Of Quadrilateral figures, a square is that which is both equilateral and right-angled; an oblong that which is right angled but not equilateral
”. > > The term ‘oblong’ is generally not used today in maths, as ‘rectangle’ seems to be more in fashion however the common definition of oblong is that an oblong is an un-equal rectangle and a square is an equal rectangle, rectangle being the shape-group these both fit into. Oblong is also sometimes referd to as the plural of rectangle, just like the word ‘rectangular’. All in all, it varies from person to person: the younger generation say rectangle and the older generation usually says oblong. The use of “maths” in this text suggests it was written by a Brit. ---
**Author:** ![GorillaMan](https://avatars.discourse-cdn.com/v4/letter/g/50afbb/32.png) [@GorillaMan](https://boards.straightdope.com/u/GorillaMan)\ **Post date:** [February 23, 2006, 9:01pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/36 "2006-02-23T21:01:09Z")
IMO time - ‘oblong’ sounds fairly old-fashioned to me ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [February 23, 2006, 9:10pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/37 "2006-02-23T21:10:26Z")
I believe that “box”, in mathematical usage, actually refers to a set in **R** [sup]n[/sup] describable by [a[sub]1[/sub],b[sub]1[/sub]] × [a[sub]2[/sub],b[sub]2[/sub]] × 
 × [a[sub]n[/sub],b[sub]n[/sub]]. So it would be quite proper to describe the figure in question as a “3-d box”, or in contexts where three dimensions may be assumed, merely “a box”. When you have a term which is both correct mathematically, instantly recognizable, and short, why not use it? ---
**Author:** ![Suburban\_Plankton](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/suburban_plankton/32/219_2.png) [@Suburban\_Plankton](https://boards.straightdope.com/u/Suburban_Plankton)\ **Post date:** [February 23, 2006, 9:23pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/38 "2006-02-23T21:23:12Z")
So, for those of you keeping score at home, we now have the following candidates: rectangular box rectangular parallelepiped rectangular prism rectangular solid limiting super ellipsoid 3d simplex cuboid hexahedron quader The first four cancel each other out. Sorry, that’s just the breaks. The definition I find for **3D Simplex** is “A Euclidean geometric spatial element having the minimum number of boundary points”. In 3-D space, this would actually be a tetrahedron. **Limiting Super Ellipsoid** sounds quite impressive, but I don’t really know what it is, no I’m discounting it. **Cuboid** is technically correct, but as previously stated sounds too much like “cube”, so it’s out as well. **Hexahedron** is good, but would apply to any three dimensional shape with six faces, so it is not specific enough. So I’m sticking with **Quader** , which, if the Google transation is to be believed, is German for “right parallelepiped”. Since English is filled with “borrowed” words already, I see no problem in adding one more to the list. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [February 23, 2006, 9:38pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/39 "2006-02-23T21:38:59Z")
Meh. Quader sounds like the name of a politician. Vote Cuboid! ---
**Author:** ![Bytegeist](https://avatars.discourse-cdn.com/v4/letter/b/9dc877/32.png) [@Bytegeist](https://boards.straightdope.com/u/Bytegeist)\ **Post date:** [February 23, 2006, 10:36pm UTC](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700/40 "2006-02-23T22:36:44Z")
> [@Suburban Plankton](#): > > **Limiting Super Ellipsoid** sounds quite impressive, but I don’t really know what it is, no I’m discounting it. A [super ellipsoid](http://www.cs.mcgill.ca/~dudek/SQ/superquadrics.html) is a three-dimensional shape that satisfies the equation: (x/a)[sup]n[/sup] + (y/b)[sup]n[/sup] + (z/c)[sup]n[/sup] = 1 As the exponent _ **n** _ gets larger and larger, the shape more and more resembles a box with dimensions 2a by 2b by 2c — though it never actually becomes such a box. Anyway, I wasn’t being serious in proposing “limiting super ellipsoid” as a replacement for “cuboid”, “rectangular prism”, or whatever. It’s just an amusing, arcane way of looking at a plain and simple shape. [Previous page](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700.md?page=1) [Next page](https://boards.straightdope.com/t/what-do-you-call-a-three-dimensional-rectangle/345700.md?page=3)