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
Jewish businesses and homes vandalized with red triangles, swastikas, or political slogans.
—
Jonathan Greenblatt, Time, 23 May 2025
In the movie, Camp and Melissa find themselves in a love triangle with his mentor, Jean-Luc La Joie from the band The Kry.
—Caroline Blair, People.com, 22 May 2025
The love triangle is a dramaturgical structure that goes on forever.
—Anne Thompson, IndieWire, 22 May 2025
The love triangle of Buchanan, his wife, Daisy, and Gatsby ends in tragedy with Tom causing the deaths of two people to cover for Daisy’s careless driving, which had resulted in another death.
—Chicago Tribune, 21 May 2025
See All Example Sentences for triangle
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Jonathan Greenblatt, Time, 23 May 2025
In the movie, Camp and Melissa find themselves in a love triangle with his mentor, Jean-Luc La Joie from the band The Kry.
—Caroline Blair, People.com, 22 May 2025
The love triangle is a dramaturgical structure that goes on forever.
—Anne Thompson, IndieWire, 22 May 2025
The love triangle of Buchanan, his wife, Daisy, and Gatsby ends in tragedy with Tom causing the deaths of two people to cover for Daisy’s careless driving, which had resulted in another death.
—Chicago Tribune, 21 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 2 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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