Given a triangle , construct the three exterior equilateral triangles on its sides with centers , , . Then the lines , , intersect at the first Napoleon point .
Let , , be the exact trilinear coordinates of with respect to ; ; , , be the side lengths of ; , , be the circumradius, inradius and semiperimeter of ; ; and set , , , to be the Conway notation, where is the Brocard angle.
A triangle center is said to be even when its barycentric coordinates can be expressed as a function of three variables , , that all occur with even exponents. If the center of a triangle has constant barycentric coordinates, it is called a neutral center (the centroid is the only neutral center). A triangle center is said to be odd if it is neither even nor neutral.
Standard barycentric coordinates of a point with respect to a reference triangle have a sum of 1.