Illustration of triangle
- 1 equilateral
- 2 acute
- 3 obtuse
- 4 scalene
- 5 isosceles
- 6 right triangle
triangle
noun
tri·an·gle
ˈtrī-ˌaŋ-gəl 
1
: a polygon having three sides compare spherical triangle
2
a
: a percussion instrument consisting of a rod of steel bent into the form of a triangle open at one angle and sounded by striking with a small metal rod
b
: a drafting instrument consisting of a thin flat right-angled triangle of wood or plastic with acute angles of 45 degrees or of 30 degrees and 60 degrees
3
: a situation in which one member of a couple is involved in a love affair with a third person
Examples of triangle in a Sentence
She cut the sandwiches into triangles.
Recent Examples on the Web
The play, a psychological thriller, presents a kind of complex love triangle.
—
Jeryl Brunner, Forbes.com, 7 June 2025
Shaped like a triangle, the 33-inch wide desk is ideal for those looking to maximize their small space’s square footage.
—Erika Owen, Architectural Digest, 3 June 2025
As for Johnson, the actress is next set to star in Celine Song’s rom-com Materialists, which also stars Chris Evans and Pedro Pascal in a love triangle with Johnson's character.
—Brenton Blanchet, People.com, 2 June 2025
This, in fact, provided high drama in the first UK season when contestants Sam, Nicole and Benaiah found themselves in such a triangle.
—Max Goldbart, Deadline, 29 May 2025
See All Example Sentences for triangle
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Jeryl Brunner, Forbes.com, 7 June 2025
Shaped like a triangle, the 33-inch wide desk is ideal for those looking to maximize their small space’s square footage.
—Erika Owen, Architectural Digest, 3 June 2025
As for Johnson, the actress is next set to star in Celine Song’s rom-com Materialists, which also stars Chris Evans and Pedro Pascal in a love triangle with Johnson's character.
—Brenton Blanchet, People.com, 2 June 2025
This, in fact, provided high drama in the first UK season when contestants Sam, Nicole and Benaiah found themselves in such a triangle.
—Max Goldbart, Deadline, 29 May 2025
See All Example Sentences for triangle
Cite this Entry
“Triangle.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/triangle. Accessed 17 Jun. 2025.
Copy CitationKids Definition
triangle
noun
tri·an·gle
ˈtrī-ˌaŋ-gəl
1
: a figure that has three sides and three angles : a polygon that has three sides
2
: a percussion instrument made of a steel rod bent into a triangle open at one corner which is played by striking with a metal rod
3
: a drafting instrument consisting of a thin flat right-angled triangle
Medical Definition
triangle
noun
tri·an·gle
ˈtrī-ˌaŋ-gəl
: a three-sided region or space and especially an anatomical one see anterior triangle, carotid triangle, femoral triangle, posterior triangle, suboccipital triangle
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