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
To do one: Lie on your back with your feet flat on the floor, so your legs form a triangle.
—
Kelly Burch Published, Verywell Health, 7 Feb. 2025
The triangle represents the colors that comprise sRGB—essentially, all the colors that can be made by mixing different percentages of red, green, and blue.
—PCMAG, 6 Feb. 2025
All three are superb and make the love triangle feel both authentic and appealing.
—Murtada Elfadl, Variety, 5 Feb. 2025
The triangle might have rotated at times, but there were multiple instances within the opening 15 minutes of the close attention being paid by Liverpool’s trio.
—Mark Carey, The Athletic, 3 Feb. 2025
See all Example Sentences for triangle 
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Kelly Burch Published, Verywell Health, 7 Feb. 2025
The triangle represents the colors that comprise sRGB—essentially, all the colors that can be made by mixing different percentages of red, green, and blue.
—PCMAG, 6 Feb. 2025
All three are superb and make the love triangle feel both authentic and appealing.
—Murtada Elfadl, Variety, 5 Feb. 2025
The triangle might have rotated at times, but there were multiple instances within the opening 15 minutes of the close attention being paid by Liverpool’s trio.
—Mark Carey, The Athletic, 3 Feb. 2025
See all Example Sentences for triangle
Dictionary Entries Near triangle
Cite this Entry
“Triangle.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/triangle. Accessed 12 Feb. 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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