Talk:Rhombus

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Hi!

My last edit request section seems to be deactivated...

Please add the missing expression of the rhombus height h in terms of the rhombus side a and any vertex angle:

${\displaystyle h=a\sin \alpha =a\sin \beta }$ ;

it can be sourced by the following website, where it is featured:

Furey, Edward. "Rhombus Calculator"; CalculatorSoup, https://www.calculatorsoup.com - Online Calculators.

Then, please add the missing expression of the rhombus height h in terms of the rhombus inradius r :

${\displaystyle h=2r}$ ; or: ${\displaystyle r={h \over 2}}$ ;

it is just mentioned in the little caption under a figure of the article:

"The height h is the perpendicular distance between any two non-adjacent sides, which equals the diameter of the circle inscribed."

Double thank you in advance!

€:-) €:-)

~~ (my Wikipedia anonymous pseudonym)

€;-)

- 2A01:CB00:8697:8100:3531:F012:5113:D6E5 (talk) 20:22, 1 December 2019 (UTC)Reply

"Alert":

the rhombus article uses the rhombus height h in 2 different area formulas:

${\displaystyle K=a\cdot h}$ , and:

${\displaystyle K={\frac {h^{2}}{\sin \alpha }}}$ ,

without providing an expression of h ,

and without noting that h is unique;

this is not "mathematically correct"...

€:-P

~~

- 2A01:CB00:8697:8100:F964:F02D:1FD7:636C (talk) 19:27, 2 December 2019 (UTC)Reply

This WP "Rhombus" article features a table classifying "Rhombic icosahedron" as having "Two types of rhombi";

the WP "Rhombic icosahedron" article says:

"A rhombic icosahedron [...] has 10 faces on the axis of symmetry with 10 rhombi following the equator. [...] all the faces are congruent [...]."

Something must be clarified, somewhere...!

RavBol (talk) 22:33, 18 December 2019 (UTC)Reply

Is there a source for the notion that the word "diamond" is sometimes used specifically for the rhombus that has a 60° angle, rather than as a synonym for "rhombus"? In any case, not all diamonds on playing cards do have this angle. And the rhombus with a 60° angle is not exactly a "projection" of adjacent faces of an octahedron. Rather it is the 2D figure you get if you rotate one of the faces about their shared edge until it is coplanar with the other face. It is a part of a 2D net of an octahedron. So the opening paragraph needs some amendment. Vumbin (talk) 22:17, 27 October 2021 (UTC)Reply

I agree with Vumbin that the reference to octahedral projections is not correct. Also, playing card diamonds do not generally have 60° angles. On the other hand, I think the reference to "diamonds" having 60° angles is from the usage as a polyiamond, where it does have to be 60°. This opening paragraph needs editing. --seberle (talk) 22:08, 20 November 2021 (UTC)Reply

Well, when it comes to "diamonds" on playing cards, some of them even have curved lines! ~2025-37436-45 (talk) 11:33, 1 December 2025 (UTC)Reply

The page says: "Other names for rhombus include diamond, lozenge, and calisson." I have searched for calisson: it does not appear in Merriam-Webster, and in other dictionaries (and a Google Books search) it is only a type of French candy/sweet lozenge. Can we source this claim that it means "rhombus" in English? ~2025-37436-45 (talk) 09:56, 1 December 2025 (UTC)Reply

The redirect 🔶 has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2026 August 13 § Orange and blue rhombi until a consensus is reached. Mathguy2718 (talk) 06:22, 13 August 2026 (UTC)Reply