The review of application of projective geometry for interpretation of growth of the human body is submitted and features of use of this geometry in the electric circuit theory are shown. Growth of the human body, the change of regime parameters of a network is interpreted as projective transformations. These transformations possess invariants, there are cross ratios of four points. The common mathematical apparatus represents interdisciplinary approach in view of analogy of processes of a different physical nature. The obtained results develop methodology of application of non-Euclidean geometries.