Tri"an`gle (?), n. [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.
&fist; 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 (Zoöl.), a small
American spider (Hyptiotes Americanus) of the family
Ciniflonidæ, 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.
Tri"an`gle (?), n. [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.
&fist; 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 (Zoöl.), a small
American spider (Hyptiotes Americanus) of the family
Ciniflonidæ, 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.
