What are the properties of an equilateral triangle?

Napoleon's theorem states that if equilateral triangles are erected on the sides of any triangle, the centers of those three triangles themselves form an equilateral triangle. If the triangles are erected outwards, as in the image on the left, the triangle is known as the outer Napoleon triangle. read more

Since the sum of a triangle's angles is always 180 degrees, each angle in an equilateral triangle must measure 60 degrees. This is because we must divide 180 degrees evenly between the three angles: 180 / 3 = 60. read more

In geometry, an equilateral triangle is a triangle in which all three sides are equal. In the familiar Euclidean geometry, equilateral triangles are also equiangular; that is, all three internal angles are also congruent to each other and are each 60°. read more