Equilateral triangle Equilateral triangle In geometry, an equilateral triangle is a triangle in which all three sides are equal. In the familiar Euclidean geometry, an equilateral triangle is also equiangular; that is, all three internal angles are also congruent to each other and are each 60°. It is also a regular polygon, so it is also referred to as a regular triangle. Denoting the common length of the sides of the equilateral triangle as "a", we can determine using the Pythagorean theorem that: Denoting the radius of the circumscribed circle as "R", we can determine using trigonometry that: Many of these quantities
Golden Triangle (Rocky Mountains) Golden Triangle (Rocky Mountains) The Golden Triangle is an informal designation for a region renowned as one of the premier fly fishing locations in the United States. The region is named for its approximate boundaries that form an equilateral triangle having an apex at Glacier National Park and encompassing Yellowstone National Park and the eastern portion of Idaho. Superior fly fishing also exists in the surrounding areas of the Rocky Mountains in Idaho and western Montana. Because of a large number of major rivers such as the Yellowstone, Madison, Gallatin, and the Blackfoot, many hundreds of fast, clear-running streams and