Marks' First Lessons in Geometry: In Two Parts is a foundational mathematics textbook authored by Bernhard Marks, meticulously crafted for young learners in primary classes, grammar schools, and academies. The book is divided into two comprehensive parts, each designed to introduce and solidify the essential principles of geometry through clear, objective presentation. The first part focuses on the basic definitions, postulates, and fundamental concepts such as points, lines, angles, surfaces, and solids, ensuring that students develop a strong grasp of the language and logic of geometry from the outset. Through a series of carefully structured lessons, the book guides students step-by-step, using simple language and numerous illustrations to make abstract ideas accessible and engaging. The second part of the book builds upon this foundation, introducing more advanced topics such as the properties of triangles, quadrilaterals, circles, and other geometric figures. It emphasizes logical reasoning and the development of problem-solving skills, encouraging students to apply what they have learned through practical exercises and questions. Each lesson is designed to be self-contained, allowing for flexible use in classroom settings or for independent study. The book’s objective approach ensures that students are not merely memorizing facts, but are actively engaging with the material, developing a deep and lasting understanding of geometric principles. With its clear explanations, systematic progression, and focus on foundational skills, Marks' First Lessons in Geometry remains a valuable resource for introducing young learners to the world of geometry.