triangular

English

A triangular sign.

Etymology

From Middle English triangulare, trianguler, triangulere, from Old French triangulaire, triangulier and Latin triangulāris. By surface analysis, tri- +‎ -angular.

Pronunciation

• (UK) IPA^(key): /tɹaɪˈæŋ.ɡjə.lə/, /tɹaɪˈæŋ.ɡjʊ.lə/
• (US) IPA^(key): /tɹaɪˈæŋ.ɡjə.lɚ/, /tɹaɪˈaɪŋ.ɡjʊ.lɚ/

• Audio (US):

  (file)

Adjective

triangular (comparative more triangular, superlative most triangular)

1. Shaped like a triangle.

   Synonym: leg-of-mutton

   • 1963, Margery Allingham, “Foreword: The Turk Street Mile”, in The China Governess: A Mystery, London: Chatto & Windus, →OCLC, page 15:

     A very neat old woman, still in her good outdoor coat and best beehive hat, was sitting at a polished mahogany table on whose surface there were several scored scratches so deep that a triangular piece of the veneer had come cleanly away, […].

2. Of, or pertaining to, triangles.
3. Having a triangle as a base; as, a triangular prism, a triangular pyramid.
4. Having three elements or parties; trilateral, tripartite.

Synonyms

• threeside, trigonal

Derived terms

• equitriangular
• nontriangular
• obtriangular
• ovotriangular
• quasitriangular
• subtriangular
• triangular colon
• triangular division
• triangular harp
• triangular hebesphenorotunda
• triangularine
• triangularity
• triangularization
• triangularize
• triangularly
• triangular matrix
• triangular number
• triangular prism
• triangular pyramid
• triangular trade
• triangulo-triangular
• unitriangular

Translations

shaped like a triangle

• Arabic: مُثَلَّث (muṯallaṯ)
• Belarusian: трохвуго́льны (troxvuhólʹny), трыку́тны (trykútny)
• Bengali: ত্রিভুজাকৃতি (tribhujakriti)
• Breton: tric'hornek (br)
• Bulgarian: триъгълен (triăgălen)
• Czech: trojúhelníkový (cs), trojúhelníkovitý (cs)
• Danish: trekantet (da)
• Dutch: driehoekig (nl)
• Esperanto: triangula
• Finnish: kolmikulmainen (fi), kolmiomainen (fi)
• French: triangulaire (fr)
• Galician: triangular (gl)
• Georgian: სამკუთხა (samḳutxa)
• German: dreieckig (de)
• Greek:

  Ancient Greek: τρίγωνος (trígōnos)

• Hungarian: háromszögletű (hu), háromszög alakú, (rare in this sense) háromszögű (hu)
• Irish: triantánach
• Italian: triangolare (it)
• Latin: triangulus m
• Manx: tree-uillinagh, tree corneilagh
• Māori: tapatoru
• Norwegian:

  Bokmål: trekantet, trekanta (no), triangulær

  Nynorsk: trekanta, triangulær

• Polish: trójkątny (pl)
• Portuguese: triangular (pt) m or f
• Russian: треуго́льный (ru) (treugólʹnyj)
• Scottish Gaelic: triantanach
• Spanish: triangular (es)
• Swedish: triangulär (sv), trekantig (sv)
• Tagalog: tatsihain
• Ukrainian: трику́тний (trykútnyj)
• Uzbek: uchburchak (uz)
• Yiddish: דרײַעקיק (drayekik), דרײַקאַנטיק (draykantik)

of or pertaining to triangles

• Bulgarian: триъгълен (triăgălen)
• Czech: trojúhelníkový (cs)
• Dutch: driehoeks-
• Esperanto: triangula
• Finnish: kolmio- (fi), kolmiomainen (fi)
• German: dreiecks- (de)
• Irish: triantánach
• Māori: tapatoru
• Polish: trójkątowy
• Portuguese: triangular (pt) m or f
• Russian: треуго́льный (ru) (treugólʹnyj)
• Scottish Gaelic: triantanach
• Spanish: triangular (es)
• Tagalog: tatsihain

having a triangle as a base

• Finnish: kolmikulmainen (fi), kolmiomainen (fi)
• Hungarian: háromszög alapú
• Irish: triantánach
• Scottish Gaelic: triantanach

having three elements or parties

• Finnish: kolmikantainen (fi)
• Hungarian: (with three parties) háromoldalú (hu), három résztvevős, (with three elements) háromrészes (hu)

The translations below need to be checked and inserted above into the appropriate translation tables. See instructions at Wiktionary:Entry layout § Translations.

Translations to be checked

• Danish: ^{(please verify)} trekantet (da)
• Dutch: ^{(please verify)} driehoekig (nl)
• German: ^{(please verify)} dreieckig (de)

Catalan

Etymology 1

Borrowed from Late Latin triangulāris.

Pronunciation

• IPA^(key): (Northern, Central) [tɾi.əŋ.ɡuˈlar]
• IPA^(key): (Balearic) [tɾi.əŋ.ɡuˈla]
• IPA^(key): (Valencia) [tɾi.aŋ.ɡuˈlaɾ]
• IPA^(key): (Northwestern) [tɾi.aŋ.ɡuˈlar]

Adjective

triangular m or f (masculine and feminine plural triangulars)

1. (geometry) triangular

Etymology 2

From Latin triangulus +‎ -ar.

Pronunciation

• IPA^(key): (Northern, Balearic, Central) [tɾi.əŋ.ɡuˈla]
• IPA^(key): (Valencia) [tɾi.aŋ.ɡuˈlaɾ]
• IPA^(key): (Northwestern) [tɾi.aŋ.ɡuˈla]

Verb

triangular (first-person singular present triangulo, first-person singular preterite triangulí, past participle triangulat)

1. (transitive) to triangulate

Conjugation

    Central Catalan conjugation of triangular (first conjugation)

infinitive			triangular
gerund			triangulant
past participle				masculine		feminine
		singular		triangulat		triangulada
		plural		triangulats		triangulades
person		singular			plural
		first	second	third	first	second	third
indicative		jo	tu	ell/ella vostè	nosaltres nós	vosaltres vós	ells/elles vostès
	present	triangulo	triangules	triangula	triangulem	trianguleu	triangulen
	imperfect	triangulava	triangulaves	triangulava	triangulàvem	triangulàveu	triangulaven
	future	triangularé	triangularàs	triangularà	triangularem	triangulareu	triangularan
	preterite	triangulí	triangulares	triangulà	triangulàrem	triangulàreu	triangularen
	conditional	triangularia	triangularies	triangularia	triangularíem	triangularíeu	triangularien
subjunctive		jo	tu	ell/ella vostè	nosaltres nós	vosaltres vós	ells/elles vostès
	present	trianguli	triangulis	trianguli	triangulem	trianguleu	triangulin
	imperfect	triangulés	triangulessis	triangulés	trianguléssim	trianguléssiu	triangulessin
imperative		—	tu	vostè	nosaltres	vosaltres vós	vostès
	affirmative	—	triangula	trianguli	triangulem	trianguleu	triangulin
	negative (no)	—	no triangulis	no trianguli	no triangulem	no trianguleu	no triangulin

Further reading

• Alcover, Antoni Maria; Moll, Francesc de Borja (1963), “triangular”, in Diccionari català-valencià-balear (in Catalan)
• “triangular” in Diccionari normatiu valencià, Acadèmia Valenciana de la Llengua.
• “triangular”, in Gran Diccionari de la Llengua Catalana, Grup Enciclopèdia Catalana, 2026
• “triangular”, in Diccionari de la llengua catalana [Dictionary of the Catalan Language] (in Catalan), second edition, Institute of Catalan Studies [Catalan: Institut d'Estudis Catalans], April 2007

Galician

Pronunciation

 

• IPA^(key): /tɾjaŋɡuˈlaɾ/ [t̪ɾjɑŋ.ɡuˈlaɾ]

• IPA^(key): (standard) /tɾjaŋɡuˈlaɾ/ [t̪ɾjɑŋ.ɡuˈlaɾ]
• IPA^(key): (gheada) /tɾjaŋħuˈlaɾ/ [t̪ɾjɑŋ.ħuˈlaɾ]

• Rhymes: -aɾ
• Hyphenation: trian‧gu‧lar

Adjective

triangular m or f (plural triangulares)

1. triangular, shaped like a triangle
2. having a triangle as a base
3. having three elements or parties

Related terms

• triángulo
• triangularmente

Further reading

• “triangular”, in Dicionario da Real Academia Galega (in Galician), A Coruña: Royal Galician Academy, 2012–2026

Portuguese

Etymology 1

Etymology tree

Proto-Indo-European *tréyes

Proto-Italic *trejes

Proto-Italic *trēs

Latin trēs

Proto-Indo-European *h₂eng-

Proto-Indo-European *h₂engulos

Proto-Italic *angulos

Latin angulus

Latin triangulus

Proto-Indo-European *h₂el-

Proto-Indo-European *-is

Proto-Indo-European *h₂élisder.?

Proto-Italic *-ālis

Latin -ālis

Latin -āris

Latin triangulārislbor.

Portuguese triangular

Learned borrowing from Latin triangulāris.

Pronunciation

 

• (Brazil) IPA^(key): /tɾi.ɐ̃.ɡuˈlaʁ/ [tɾi.ɐ̃.ɡuˈlah], (faster) /tɾjɐ̃.ɡuˈlaʁ/ [tɾjɐ̃.ɡuˈlah]

• (Brazil) IPA^(key): /tɾi.ɐ̃.ɡuˈlaʁ/ [tɾi.ɐ̃.ɡuˈlah], (faster) /tɾjɐ̃.ɡuˈlaʁ/ [tɾjɐ̃.ɡuˈlah]
  • (São Paulo) IPA^(key): /tɾi.ɐ̃.ɡuˈlaɾ/, (faster) /tɾjɐ̃.ɡuˈlaɾ/
  • (Rio de Janeiro) IPA^(key): /tɾi.ɐ̃.ɡuˈlaʁ/ [tɾi.ɐ̃.ɡuˈlaχ], (faster) /tɾjɐ̃.ɡuˈlaʁ/ [tɾjɐ̃.ɡuˈlaχ]
  • (Caipira) IPA^(key): /tɾi.ɐ̃.ɡuˈlaɻ/, (faster) /tɾjɐ̃.ɡuˈlaɻ/

 

• (Portugal) IPA^(key): /tɾi.ɐ̃.ɡuˈlaɾ/, (faster) /tɾjɐ̃.ɡuˈlaɾ/

• (Portugal) IPA^(key): /tɾi.ɐ̃.ɡuˈlaɾ/, (faster) /tɾjɐ̃.ɡuˈlaɾ/
  • (Southern Portugal) IPA^(key): /tɾi.ɐ̃.ɡuˈla.ɾi/, (faster) /tɾjɐ̃.ɡuˈla.ɾi/

• Hyphenation: tri‧an‧gu‧lar

Adjective

triangular m or f (plural triangulares)

1. (geometry) triangular

Related terms

• triângulo

Etymology 2

Etymology tree

Proto-Indo-European *tréyes

Proto-Italic *trejes

Proto-Italic *trēs

Latin trēs

Proto-Indo-European *h₂eng-

Proto-Indo-European *h₂engulos

Proto-Italic *angulos

Latin angulus

Latin triangulus

Proto-Italic *-āzi

▲

Latin -ereinflu.

Latin -āre

Old Galician-Portuguese -ar

Portuguese -ar

Portuguese triangular

From Latin triangulus + Portuguese -ar.

Pronunciation

 

• (Brazil) IPA^(key): /tɾi.ɐ̃.ɡuˈla(ʁ)/ [tɾi.ɐ̃.ɡuˈla(h)], (faster) /tɾjɐ̃.ɡuˈla(ʁ)/ [tɾjɐ̃.ɡuˈla(h)]

• (Brazil) IPA^(key): /tɾi.ɐ̃.ɡuˈla(ʁ)/ [tɾi.ɐ̃.ɡuˈla(h)], (faster) /tɾjɐ̃.ɡuˈla(ʁ)/ [tɾjɐ̃.ɡuˈla(h)]
  • (São Paulo) IPA^(key): /tɾi.ɐ̃.ɡuˈla(ɾ)/, (faster) /tɾjɐ̃.ɡuˈla(ɾ)/
  • (Rio de Janeiro) IPA^(key): /tɾi.ɐ̃.ɡuˈla(ʁ)/ [tɾi.ɐ̃.ɡuˈla(χ)], (faster) /tɾjɐ̃.ɡuˈla(ʁ)/ [tɾjɐ̃.ɡuˈla(χ)]
  • (Caipira) IPA^(key): /tɾi.ɐ̃.ɡuˈla(ɻ)/, (faster) /tɾjɐ̃.ɡuˈla(ɻ)/

 

• (Portugal) IPA^(key): /tɾi.ɐ̃.ɡuˈlaɾ/, (faster) /tɾjɐ̃.ɡuˈlaɾ/

• (Portugal) IPA^(key): /tɾi.ɐ̃.ɡuˈlaɾ/, (faster) /tɾjɐ̃.ɡuˈlaɾ/
  • (Southern Portugal) IPA^(key): /tɾi.ɐ̃.ɡuˈla.ɾi/, (faster) /tɾjɐ̃.ɡuˈla.ɾi/

• Hyphenation: tri‧an‧gu‧lar

Verb

triangular (first-person singular present triangulo, first-person singular preterite triangulei, past participle triangulado)

1. (transitive) to triangulate

Conjugation

    Conjugation of triangular (See Appendix:Portuguese verbs)

	Singular			Plural
	First-person (eu)	Second-person (tu)	Third-person (ele / ela / você)	First-person (nós)	Second-person (vós)	Third-person (eles / elas / vocês)
Infinitive
Impersonal	triangular
Personal	triangular	triangulares	triangular	triangularmos	triangulardes	triangularem
Gerund
	triangulando
Past participle
Masculine	triangulado			triangulados
Feminine	triangulada			trianguladas
Indicative
Present	triangulo	triangulas	triangula	triangulamos	triangulais	triangulam
Imperfect	triangulava	triangulavas	triangulava	triangulávamos	trianguláveis	triangulavam
Preterite	triangulei	triangulaste	triangulou	triangulamos1, triangulámos2	triangulastes	triangularam
Pluperfect	triangulara	triangularas	triangulara	trianguláramos	trianguláreis	triangularam
Future	triangularei	triangularás	triangulará	triangularemos	triangulareis	triangularão
Conditional	triangularia	triangularias	triangularia	triangularíamos	triangularíeis	triangulariam
Subjunctive
Present	triangule	triangules	triangule	triangulemos	trianguleis	triangulem
Imperfect	triangulasse	triangulasses	triangulasse	triangulássemos	triangulásseis	triangulassem
Future	triangular	triangulares	triangular	triangularmos	triangulardes	triangularem
Imperative
Affirmative		triangula	triangule	triangulemos	triangulai	triangulem
Negative (não)		não triangules	não triangule	não triangulemos	não trianguleis	não triangulem

¹Brazilian Portuguese.
²European Portuguese.

Derived terms

• triangulação

Further reading

• “triangular”, in Dicionário Aulete Digital (in Portuguese), Rio de Janeiro: Lexikon Editora Digital, 2008–2026
• “triangular”, in Dicionário inFormal (in Portuguese), 2006–2026
• “triangular” in Dicionário Aberto based on Novo Diccionário da Língua Portuguesa de Cândido de Figueiredo, 1913
• “triangular”, in Dicionário Infopédia da Língua Portuguesa (in Portuguese), Porto: Porto Editora, 2003–2026
• “triangular”, in Michaelis Dicionário Brasileiro da Língua Portuguesa (in Portuguese), São Paulo: Editora Melhoramentos, 2015–2026, →ISBN
• “triangular”, in Dicionário Priberam da Língua Portuguesa (in Portuguese), Lisbon: Priberam, 2008–2026

Romanian

Etymology

Borrowed from French triangulaire.

Adjective

triangular m or n (feminine singular triangulară, masculine plural triangulari, feminine/neuter plural triangulare)

1. triangular

Declension

Declension of triangular

		singular			plural
		masculine	neuter	feminine	masculine	neuter	feminine
nominative- accusative	indefinite	triangular		triangulară	triangulari	triangulare
	definite	triangularul		triangulara	triangularii	triangularele
genitive- dative	indefinite	triangular		triangulare	triangulari	triangulare
	definite	triangularului		triangularei	triangularilor	triangularelor

Spanish

Pronunciation

• IPA^(key): /tɾjanɡuˈlaɾ/ [t̪ɾjãŋ.ɡuˈlaɾ]
• Rhymes: -aɾ
• Syllabification: trian‧gu‧lar

Etymology 1

Etymology tree

Proto-Indo-European *tréyes

Proto-Italic *trejes

Proto-Italic *trēs

Latin trēs

Proto-Indo-European *h₂eng-

Proto-Indo-European *h₂engulos

Proto-Italic *angulos

Latin angulus

Latin triangulus

Proto-Indo-European *h₂el-

Proto-Indo-European *-is

Proto-Indo-European *h₂élisder.?

Proto-Italic *-ālis

Latin -ālis

Latin -āris

Late Latin triangulārisbor.

Spanish triangular

Borrowed from Late Latin triangulāris.

Adjective

triangular m or f (masculine and feminine plural triangulares)

1. (geometry) triangular

Etymology 2

Etymology tree

Proto-Indo-European *tréyes

Proto-Italic *trejes

Proto-Italic *trēs

Latin trēs

Proto-Indo-European *h₂eng-

Proto-Indo-European *h₂engulos

Proto-Italic *angulos

Latin angulus

Latin triangulus

Spanish -ar

Spanish triangular

From Latin triangulus + Spanish -ar.

Verb

triangular (first-person singular present triangulo, first-person singular preterite triangulé, past participle triangulado)

1. (transitive) to triangulate

Conjugation

    Conjugation of triangular (See Appendix:Spanish verbs)

infinitive			triangular
gerund			triangulando
past participle				masculine		feminine
		singular		triangulado		triangulada
		plural		triangulados		trianguladas
		singular			plural
		1st person	2nd person	3rd person	1st person	2nd person	3rd person
indicative		yo	tú vos	él/ella/ello usted	nosotros nosotras	vosotros vosotras	ellos/ellas ustedes
	present	triangulo	triangulastú triangulásvos	triangula	triangulamos	trianguláis	triangulan
	imperfect	triangulaba	triangulabas	triangulaba	triangulábamos	triangulabais	triangulaban
	preterite	triangulé	triangulaste	trianguló	triangulamos	triangulasteis	triangularon
	future	triangularé	triangularás	triangulará	triangularemos	triangularéis	triangularán
	conditional	triangularía	triangularías	triangularía	triangularíamos	triangularíais	triangularían
subjunctive		yo	tú vos	él/ella/ello usted	nosotros nosotras	vosotros vosotras	ellos/ellas ustedes
	present	triangule	triangulestú triangulésvos2	triangule	triangulemos	trianguléis	triangulen
	imperfect (ra)	triangulara	triangularas	triangulara	trianguláramos	triangularais	triangularan
	imperfect (se)	triangulase	triangulases	triangulase	triangulásemos	triangulaseis	triangulasen
	future1	triangulare	triangulares	triangulare	trianguláremos	triangulareis	triangularen
imperative		—	tú vos	usted	nosotros nosotras	vosotros vosotras	ustedes
	affirmative		triangulatú triangulávos	triangule	triangulemos	triangulad	triangulen
	negative		no triangules	no triangule	no triangulemos	no trianguléis	no triangulen

¹Rare; now chiefly used in legal language.
²Argentine and Uruguayan voseo prefers the tuteo-form for the present subjunctive.

Derived terms

• triangulación

Further reading

• “triangular”, in Diccionario de la lengua española [Dictionary of the Spanish Language] (in Spanish), online version 23.8.1, Royal Spanish Academy [Spanish: Real Academia Española], 15 December 2025