Hüsnü Hamid Sayman's book named a modern approach to geometry and its evaluation

In this thesis study, Hüsnü Hamid Sayman's book Yeni Usûl Hendese, one of the geometry books taught in girls' and boys' teacher training schools in the first years of the Early Republic Period, was examined. Hüsnü Hamid Sayman, in addition to being the mathematician who produced the most works during his time at Dârülfünȗn, became an exemplary educator in his field with his diligence and success. In order to analyze the text of the Yeni Usûl Hendese textbook written in Ottoman Turkish, the contents of the first volume of the work were transcribed. Thus, the work, whose content was translated into today's Turkish, was evaluated in terms of today's modern educational approaches. By questioning the foundations of mathematics education in the said period, the mathematics education methods and techniques used in the writing of Hüsnü Hamid's mathematics textbooks were determined. As a result of this examination, the spiral approach was used in the work in question, and among the modern teaching principles and methods, the principle of establishing relationships (thematicity), induction, the principle of readiness, the principle of preliminary information-warning, the principle of clarity, the principle of technology-equipment use and finally, it was determined that the evaluation principle was used. Yeni Usûl Hendese, a textbook taught in teacher training schools, is important in terms of its content in terms of revealing the teacher training and mathematics teaching methods and techniques of the Early Republican Period. With this thesis study, the work in question has been introduced to the literature.