Barycentric coordinates (t_1, t_2, t_3) normalized so that they become the areas of the triangles P A_1 A_2, P A_1 A_3, and P A_2 A_3, where P is the point whose coordinates have been specified, normalized by the area of the original triangle Δ A_1 A_2 A_3. This is equivalent to application of the normalization relation t_1 + t_2 + t_3 = 1 (Coxeter 1969, p. 218).