TRIangel

Triangel is the German word for triangle. It can refer to the geometric figure, the percussion instrument, or as a proper noun in some place names or surnames in German-speaking regions.

In geometry, a triangle is a polygon with three sides and three vertices. The interior angles sum to 180 degrees. Triangles are classified by sides as equilateral (all sides equal), isosceles (two sides equal), or scalene (all sides different), and by angles as acute (all angles less than 90°), right (one angle exactly 90°), or obtuse (one angle greater than 90°). The area can be calculated as base times height divided by two, or with Heron's formula when all three sides are known. Triangles are foundational in geometry and appear throughout mathematics, design, and engineering.

Triangel (instrument) refers to a small metal frame bent into a triangle with one side open. It is typically hung by a loop and struck with a metal beater to produce a bright, ringing tone. The instrument is usually nondistinct in pitch or only weakly pitched and is used in orchestras, bands, percussion ensembles, and educational settings to add high-frequency color.

Other uses of the term include its appearance as a proper noun in various contexts, such as place names or surnames in German-speaking areas. In general language use, the English equivalent is triangle.