different between triangle vs disphenoid

English

Etymology

From Middle English triangle, from Old French triangle, from Latin triangulum, noun use of adjective triangulus (“three-cornered, having three angles”), from tr?s (“three”) + angulus (“corner, angle”).

Pronunciation

• (UK) IPA^(key): /?t?a?????l/, /?t?a??æ???l/
• (US) enPR: tr?'-?ng-g?l, IPA^(key): /?t?a??æ???l/
• Rhymes: -a?æ???l
• Hyphenation: tri?an?gle

Noun

triangle (plural triangles)

1. (geometry) A polygon with three sides and three angles.
2. (US, Canada) A set square.
3. (music) A percussion instrument made by forming a metal rod into a triangular shape which is open at one angle. It is suspended from a string and hit with a metal bar to make a resonant sound.
4. (cue sports) A triangular piece of equipment used for gathering the balls into the formation required by the game being played.
5. A love triangle.
   • 2009, Neil McDonald, Quadrant, November 2009, No. 461 (Volume LIII, Number 11), Quadrant Magazine Limited, page 104:

     One of the writers' most pleasing inventions was to treat the triangle love story as comedy.

6. (systemics) The structure of systems composed with three interrelated objects.
7. A draughtsman's square in the form of a right-angled triangle.
8. (historical, usually in the plural) A frame formed of three poles stuck in the ground and united at the top, to which people were bound when undergoing corporal punishment.
9. Any of various large papilionid butterflies of the genus Graphium.

   Synonym: bluebottle

10. (rail transport) A triangular formation of railway tracks, with a curve on at least one side.

    Synonym: wye

Synonyms

• (polygon): threeside, trigon (rare)
• (love triangle): love triangle, menage à trois
• See also Thesaurus:triangle

Derived terms

Translations

Further reading

• Triangle on Wikipedia.Wikipedia
• Triangle (disambiguation) on Wikipedia.Wikipedia
• Triangle (instrument) on Wikipedia.Wikipedia

Anagrams

• INTEGRAL, alerting, altering, integral, relating, tanglier, teraglin

Catalan

Etymology

From Latin triangulum.

Pronunciation

• (Balearic, Central) IPA^(key): /t?i?a?.?l?/
• (Valencian) IPA^(key): /t?i?a?.?le/

Noun

triangle m (plural triangles)

1. (geometry) triangle
2. (music) triangle

Related terms

• triangular

Further reading

• “triangle” in Diccionari de la llengua catalana, segona edició, Institut d’Estudis Catalans.
• “triangle” in Gran Diccionari de la Llengua Catalana, Grup Enciclopèdia Catalana.
• “triangle” in Diccionari normatiu valencià, Acadèmia Valenciana de la Llengua.
• “triangle” in Diccionari català-valencià-balear, Antoni Maria Alcover and Francesc de Borja Moll, 1962.

French

Etymology

Borrowed from Latin triangulum. Synchronically analysable as tri- +? angle.

Pronunciation

• IPA^(key): /t?i.j???l/

Noun

triangle m (plural triangles)

1. (geometry) triangle (polygon)

2. (music) triangle (percussion instrument)

Derived terms

• triangle amoureux
• triangle de sécurité
• triangulaire

Further reading

• “triangle” in Trésor de la langue française informatisé (The Digitized Treasury of the French Language).

Anagrams

• intégral

English

Etymology

From di- (“twice, double”) +? sphenoid (“wedge-shaped crystal or bone of the skull”).

Adjective

disphenoid (not comparable)

1. (mineralogy) Of or pertaining to a wedge-shaped crystal form of the tetragonal or orthorhombic system.
2. (mineralogy) Of or pertaining to a crystal form bounded by eight scalene triangles arranged in pairs, constituting a tetragonal scalenohedron.

Noun

disphenoid (plural disphenoids)

1. (geometry) A non-regular tetrahedron whose four faces are congruent acute-angled triangles.
   • 1973, H. S. M. Coxeter, 3rd Edition, unnumbered page,

     To make a model of a disphenoid, cut out an acute angled triangle and fold it along the joins of the mid-points of the sides. The disphenoid is said to be rhombic or tetragonal according as the triangle is isosceles or scalene.

   • 1977, Elizabeth A. Wood, Crystals and Light: An Introduction to Optical Crystallography, 2nd Revised Edition, page 8,

     If you rotate the [tetragonal] disphenoid 90° around its 2-fold axis and then perform the operation of inversion through the center-point of the object, it will occupy its original position again.

   • 1993, Horst Martini, A Hierarchical Classification of Euclidean Polytopes with Regularity Properties, Tibor Bisztriczky, Peter McMullen, Rolf Schneider, Asia Ivic Weiss (editors), Polytopes: Abstract, Convex and Computational, Proceedings of the NATO Advanced Study Institute, page 83,

     In addition it should be remarked that there are two types of disphenoids, with different symmetries: the tetragonal disphenoid (having isosceles facets) and the rhombic one.

Synonyms

• (non-regular tetrahedron with congruent faces): bisphenoid, equifacial tetrahedron, isosceles tetrahedron

Derived terms

• rhombic disphenoid
• snub disphenoid
• tetragonal disphenoid