Each point i has hyperbolic polar coordinates (r_i,\\ theta_i) and the hyperbolic law of cosines allows to measure the distance d--between two points i and j.
Each point i has hyperbolic polar coordinates (r_i,\\ theta_i) with 0\\ leqr_i\\ leq R and 0\\ leq\\ theta_i. The hyperbolic law of cosines allows to measure the distance d--between two points i and j.