Although research highlights the importance of analyzing the geometric work of teachers, there are few validated instruments in this line. This study presents the processes of design and validation of a forced-choice questionnaire that allows the characterization, from a theoretical basis, of how geometry teachers organize their teaching practice. From the theoretical perspective of mathematical working spaces, dimensions and subdimensions were structured. Content validation was achieved by submitting the questionnaire for expert judgment. To analyze the internal consistency, Aiken's V coefficient and Kendall's coefficient of concordance were used. The results permitted the general structure of the instrument to be maintained. The final version of the instrument consists of 23 items organized into 3 theoretically sustained dimensions, allowing the exploration of geometry teaching practices among mathematics teachers.