The Theory of Plasticity . Flat task. Extreme Principles and Energy Solutions. Laws, Equations, and Problems Cycles by B. T. Sapunova is a deep and fascinating immersion into the world of materials mechanics, which will become an indispensable tool for both students and practicing engineers. This publication offers readers a unique perspective on the theory of plasticity, revealing the complex aspects and principles that underlie the behavior of materials under the influence of external forces. Sapunov, known for his work in the field of mechanics and materials science, offers the reader not just a set of formulas and theories, but a whole philosophy that helps to understand how and why materials behave this way. The book covers flat tasks, making it particularly relevant to engineers working in the field of construction design, mechanical engineering, and other related disciplines. The reader will be able to get acquainted with extreme principles and energy methods of solution, which will allow him not only to solve practical problems, but also to understand more deeply the physics of the processes occurring in materials. This book will be of interest to students of technical specialties, graduate students, as well as engineers and researchers working in the field of mechanics and materials science. If you are interested in the issues of strength and stability of structures, if you are interested in how materials react to loads, then the Theory of Plasticity will be a real discovery for you. Sapunov not only explains complex concepts, but also makes it an accessible language, which makes it easy to absorb material even for those who are just starting their way in this area. The topics raised in the book cover a wide range of issues related to plasticity and material mechanics. The author examines laws, equations and problems in detail, which allows the reader not only to get acquainted with the theory, but also to apply it in practice. The book stands out for its structure: each chapter logically follows from the previous one, which creates a holistic understanding of the topic. Sapunov focuses on the importance of extreme principles, which allows finding optimal solutions for complex engineering problems. The author's style is distinguished by clarity and consistency. He masterfully combines theoretical aspects with practical examples, which makes reading not only useful, but also fascinating. In. T. Sapunov is the author of several other well-known works in the field of mechanics, and his experience and deep knowledge in this field make his work especially valuable for professionals. By reading the Theory of Plasticity, you will not only gain new knowledge, but also be able to assess the level of scientific thought that the author brings to his research. If you are looking for a book that will help you understand the intricacies of material mechanics, develop your skills and deepen your knowledge, then the Theory of Plasticity T. Sapunova is exactly what you need. It will become your reliable companion in the study of complex issues related to plasticity, and will help you become a real expert in this field. Do not miss the opportunity to touch the science that shapes the future of engineering!