Pronunciation: [tɹˈa͡ɪaŋɡə͡l] (IPA) 
Triangle is a commonly used geometrical term that refers to a three-sided figure. The spelling of the word "triangle" is quite straightforward: /ˈtraɪæŋɡl/. This can be broken down into three syllables, with the stress on the first syllable "tri." The "a" in "tri" is pronounced as in "trap," and the "i" in "angle" is pronounced as in "eye." Finally, the "e" at the end of "angle" is silent, as is common in many English words.
A triangle is a three-sided polygon, characterized by three straight sides and three interior angles. It is one of the simplest geometric shapes, possessing three vertices and three edges. Each vertex is formed by the intersection of two sides, and the three sides of the triangle do not lie in a straight line. The sum of the three angles within a triangle always equals 180 degrees.
Triangles can be classified in various ways based on their side lengths and angles. In terms of sides, a triangle can be described as equilateral, isosceles, or scalene. An equilateral triangle has three equal side lengths, while an isosceles triangle has two equal sides. A scalene triangle, on the other hand, has no equal sides. In terms of angles, triangles can be classified as acute, obtuse, or right. An acute triangle has three acute angles (each less than 90 degrees), an obtuse triangle has one obtuse angle (more than 90 degrees), and a right triangle has one right angle (exactly 90 degrees).
Triangles are utilized in many areas of mathematics, including trigonometry and geometry. They serve as a fundamental building block for many other geometric shapes, and their properties and relationships are extensively studied. Triangles also find practical applications in various fields such as architecture, engineering, and physics, where their properties are utilized to determine distances, angles, and forces.
1. A geometrical figure having three straight lines, joined two by two, forming three angles; trigone. 2. In anatomy and surgery, a more or less triangular area bounded by muscles, bony prominences, or other structures, within which are normally found certain important nerves or blood-vessels; for these various triangles (Petit's, Scarpa's, etc.) see the proper names.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
A plane figure bounded by three straight lines, having three corners or angles; anything in the form of a triangle.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.
* The statistics data for these misspellings percentages are collected from over 15,411,110 spell check sessions on www.spellchecker.net from Jan 2010 - Jun 2012.
The word "triangle" originated from the Latin word "triangulum", which is a combination of two Latin elements: "tri-", meaning "three", and "angulum", meaning "angle". This reflects the geometry of a triangle, which consists of three angles and three sides. The term was later adopted into Old French as "triangle", before being borrowed into Middle English.
