barycentric coordinates

position relative to the verticles of a triangle

In a triangle ABC we can define the position of a point P relatively to the verticles of the triangle using Point Vectors to these verticles. These three vectors form the unit vectors of the barycentric coordinate system. Every point in the plane has got three coordinate numbers. We can calculate these coordinate numbers out of the cartesian coordinates of A, B, C and P. Note that the sum of the coordinate numbers equals 1.