Definition
A triangle is a polygon with three edges and three vertices. It is one of the basic shapes in geometry. A triangle can be classified by various properties relating to its angles and sides. Based on angles, triangles can be categorized as acute (all angles less than 90°), right (one angle exactly 90°), and obtuse (one angle greater than 90°). Based on side lengths, triangles are identified as equilateral (all sides equal), isosceles (two sides equal), or scalene (no sides equal).
Etymology and Origin
The word triangle derives from the Latin triangulum, “tri-” coming from the Greek word “τρία” (tria), meaning “three”, and the Latin angulus, meaning “angle” or “corner”. This etymology reflects the geometric shape’s defining features: it has three angles and three corners or vertices. The term has been used in English since the 14th century to describe this basic and fundamental geometric figure.
1 comment