The study of physical models is generally modeled by means of partial differential equations which is still an open field in current research, such is the case of Laplace's differential equation which is surely one of the most important representations of the telecommunications industry. In the following article we will use techniques based on finite elements, through this technique we will find the behavior of the electrostatic potential in each part of the conductor: dielectric conductive material and armored material. The configuration of the coaxial cable allows to find the distribution of the dielectric displacement in the entire composition of the same in such a way that it guarantees the maximum data transfer as the signal transmission frequency increases and the attenuation of the external interference signals increases. In the first section we propose to obtain the linear terms that will calculate the weights of the values of a linear combination that numerically approximates the variable of interest through Galerkin's residual theory applying the finite element method, which for the two-dimensional case with elements Triangular linear lines that discretize the cross section of the coaxial cable, in such a way that it is easier to find these constants including the initial conditions and contour, thus allowing to guarantee the existence of a numerical solution.