This lecture covers slope stability analysis methods, including Bishop, Janbu, and Morgenstern-Price methods, developed in the 1950s and 1960s. It explains the principles of resolving slope stability problems, such as choosing a potential slip surface, calculating the factor of safety, and testing for minimum safety. The lecture also discusses the simplifying assumptions common to all slice methods and the software GeoSlope for automatically finding critical surfaces. Additionally, it introduces the finite element method for analyzing soil structures. The presentation includes detailed explanations, equations, and examples of applying these methods in geotechnical engineering.