This study investigates the efficacy of GeoGebra software in enhancing in-service mathematics teachers' instructional strategies in Euclidean geometry. Employing a quantitative research design, the study engaged 29 in-service teachers from 12 schools, utilizing pre- and post-questionnaires to assess changes in their technological, pedagogical, and content knowledge (TPACK). The training program focused on equipping teachers with skills to integrate GeoGebra into their geometry teaching. The findings suggest significant improvements in teachers’ TPACK post-training, with notable increases in confidence and perceived effectiveness in student learning. The study underscores the potential of digital tools like GeoGebra in revolutionizing mathematics education, highlighting the need for continued professional development in technology integration for teachers. This research contributes to the growing body of literature on educational technology in mathematics, offering insights for educators, policymakers, and curriculum developers on leveraging digital tools for enhanced pedagogical strategies.