Definify.com

Webster 1913 Edition

Triangle

Tri′anˊgle

,
Noun.
[L.
triangulum
, fr.
triangulus
triangular;
tri-
(see
Tri-
) +
angulus
angle: cf. F.
triangle
. See
Angle
a corner.]
1.
(Geom.)
A figure bounded by three lines, and containing three angles.
☞ A triangle is either plane, spherical, or curvilinear, according as its sides are straight lines, or arcs of great circles of a sphere, or any curved lines whatever. A plane triangle is designated as scalene, isosceles, or equilateral, according as it has no two sides equal, two sides equal, or all sides equal; and also as right-angled, or oblique-angled, according as it has one right angle, or none; and oblique-angled triangle is either acute-angled, or obtuse-angled, according as all the angles are acute, or one of them obtuse. The terms scalene, isosceles, equilateral, right-angled, acute-angled, and obtuse-angled, are applied to spherical triangles in the same sense as to plane triangles.
2.
(Mus.)
An instrument of percussion, usually made of a rod of steel, bent into the form of a triangle, open at one angle, and sounded by being struck with a small metallic rod.
3.
A draughtsman’s square in the form of a right-angled triangle.
4.
(Mus.)
A kind of frame formed of three poles stuck in the ground and united at the top, to which soldiers were bound when undergoing corporal punishment, – now disused.
5.
(Astron.)
(a)
A small constellation situated between Aries and Andromeda.
(b)
A small constellation near the South Pole, containing three bright stars.
Triangle spider
(Zool.)
,
a small American spider (
Hyptiotes Americanus
) of the family
Ciniflonidae
, living among the dead branches of evergreen trees. It constructs a triangular web, or net, usually composed of four radii crossed by a double elastic fiber. The spider holds the thread at the apex of the web and stretches it tight, but lets go and springs the net when an insect comes in contact with it.

Webster 1828 Edition

Triangle

TRI'ANGLE

,
Noun.
[L. triangulum; tres, tria, three, and angulus, a corner.] In geometry, a figure bounded by three lines, and containing three angles. The three angles of a triangle are equal to two right angles, or the number of degrees in a semicircle.
If the three lines or sides of a triangle are all right, it is a plane or rectilinear triangle.
If all the three sides are equal, it is an equilateral triangle.
If two of the sides only are equal, it is an isosceles or equicrural triangle.
If all the three sides are unequal, it is a scalene or scalenous triangle.
If one of the angles is a right angle, the triangle is rectangular.
If one of the angles is obtuse, the triangle is called obtusangular or amblygonous.
If all the angles are acute, the triangle is acutangular or oxygonous.
If the three lines of a triangle are all curves, the triangle is said to be curvilinear.
If some of the sides are right and others curve, the triangle is said to be mixtilinear.
If the sides are all arcs of great circles of the sphere, the triangle is said to be spherical.

Definition 2024

Triangle

Triangle

See also: triangle

English

Proper noun

Triangle

  1. The area comprising the cities of Raleigh, Durham and Chapel Hill in North Carolina. Used with "the" except when attributive.
    I moved to the Triangle two years ago.
    Many Triangle residents enjoy iced tea.

Anagrams

triangle

triangle

See also: Triangle

English

A regular triangle, the geometric shape.
A triangle, the musical instrument.

Noun

triangle ‎(plural triangles)

  1. (geometry) A polygon with three sides and three angles.
  2. (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.
  3. (cue sports) A triangular piece of equipment used for gathering the balls into the formation required by the game being played.
  4. 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.
  5. (systemics) The structure of systems composed with three interrelated objects.
  6. A draughtsman's square in the form of a right-angled triangle.
  7. (historical) A frame formed of three poles stuck in the ground and united at the top, to which soldiers were bound when undergoing corporal punishment.

Synonyms

Derived terms

Translations

External links

Anagrams

Catalan

Noun

triangle m ‎(plural triangles)

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

Related terms

French

Pronunciation

  • IPA(key): /tʁi.jɑ̃ɡl/

Noun

triangle m ‎(plural triangles)

  1. triangle (polygon)
  2. triangle (percussion instrument)

Derived terms

Anagrams

Etymology

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

Pronunciation

  • enPR: trī'-ăng-gəl, IPA(key): /ˈtraɪˌæŋgəl/
  • Rhymes: -aɪæŋgəl
  • Hyphenation: tri‧an‧gle

Similar Results