This third volume in the series Fundamentals of Electrical and Electronic Technologies deals with the main and most popular methods of solving electrical networks. We discuss superposition of effects, star- delta transformations, Kichhoff's principles of course, node potentials analysis, Millman's theorem. Special consideration deserves Thévenin's theorem (with its dual Norton's theorem), a very powerful tool for simplification of complex networks, but often difficult in understanding and application. An attempt has been made here to offer both the demonstration and possible applications, with attention to detail and clarity. This basic course is suitable for students as well as for workers who have undertaken a retraining program. The "Let's Try Together" sections provide materials and examples for concrete verification of the theoretical aspects. FUNDAMENTALS OF ELECTRICAL AND ELECTRONIC TECHNOLOGIES Vol. 1 - Ohm's Law Vol. 2 - Electrical Circuits Vol. 3 - Kirchhoff, Millman, Thévenin, Norton SANDRO RONCA After studying Physics at the University of Padua, he devoted himself to teaching Electrical and Electronic Technologies and Computer Science at Technical and Technological Institutes, taking care of the didactic aspects of the subject. He has delved into the study of computer networks and designed, at the request of Industrial Associations, courses for System Analysts and Computer Security Officers.