Dictionary > Triangle

Triangle

triangle
1. (Science: geometry) 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. 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. 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. (Science: astronomy) A small constellation situated between aries and andromeda. A small constellation near the south pole, containing three bright stars.
(Science: zoology) Triangle spider, 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 fibre. 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.
Origin: L. Triangulum, fr. Triangulus triangular; tri- (see Tri-) – angulus angle: cf. F. Triangle. See Angle a corner.


You will also like...

Pikas are an indicator species for climate change
Indicator Species and Endangered Species

Certain species are capable of expressing characteristics indicative of the state of the ecosystem they occupy. They are..

An artist depiction of a Precambrian multicellular life form.
The Evolution of Cell Organelles

The nucleus containing the genetic material, DNA, and the mitochondria, well-identified as the "powerhouse of the cell",..

Cell Respiration
Cell Respiration

Cell respiration is the process of creating ATP. It is "respiration" because it utilizes oxygen. Know the different stag..

Genetic Mutations
Chromosome Mutations – II

This tutorial is a continuation of the first lesson on chromosomal mutation. Here, find out the chromosomal aberrations ..

DNA carries genes coding for proteins
Genetic Information and Protein Synthesis

Genes are expressed through the process of protein synthesis. This elaborate tutorial provides an in-depth review of the..

dinosaurs
The Dinosaurs

Dinosaurs represented a major turn in the evolutionary development of organisms on Earth. The first dinosaurs were presu..