(mathematics) A group that can be realized geometrically by sequences of reflections across the sides of a triangle.

A region of Central America consisting of Guatemala, El Salvador, and Honduras.

plural of color triangle

A region bounded by the vertices at Reno, Nevada, USA; Las Vegas, Nevada, USA; Fresno, California, USA; containing part of the Sierra Nevadas (a mountain range in the Rocky Mountain Cordillera); the triangle falling mostly in the U.S. state of Nevada; where many plane crashes occur and planes disappear.

A region of Bolivia, Chile, Argentina, in the Atacama Desert, which produces much of the world's lithium supply, and contain most of the known world lithium reserves

plural of golden triangle

An area that is dangerous and where people or vessels may disappear. / A set of three things considered dangerous.

A region of West Yorkshire, between Wakefield, Morley and Rothwell, famous for producing early forced rhubarb.

plural of Pascal's triangle

A region of the Pacific Ocean, settled by Polynesians, that is roughly triangular, extending from vertexes approximately at New Zealand, Easter Island, Hawaii. This is sometimes used to define the region of Polynesia.