This lecture covers the geometric principles relevant to architecture, focusing on hyperboloids and paraboloids. It begins with an introduction to the characteristics of these surfaces, including their equations and properties. The instructor discusses the construction of hyperboloids and their applications in architectural design, emphasizing their unique structural advantages. The lecture also explores the mathematical foundations of these shapes, including curvature and the implications of different geometric configurations. Various examples of hyperboloid and paraboloid structures in real-world architecture are presented, illustrating their aesthetic and functional benefits. The discussion includes the importance of understanding these forms in the context of architectural design and engineering, as well as their role in creating innovative and sustainable structures. The lecture concludes with a summary of key concepts and their relevance to modern architectural practices, encouraging students to consider the integration of these geometric forms in their future projects.