GeoGebra, a dynamic mathematics software, was used to study high school students' perceptions and achievements in learning trigonometric ratios. The study addresses a critical gap in the literature concerning the use of GeoGebra for understanding trigonometric concepts, particularly in fostering conceptual clarity and problem-solving skills. Rooted in a constructivist pedagogical framework, the research examines how GeoGebra facilitates interactive and exploratory learning environments that encourage active student engagement and deeper comprehension of trigonometric ratio principles. The study employed a quantitative approach to evaluate the efficacy of GeoGebra. Quantitative data focused on student achievement in solving trigonometric ratio problems through pre- and post-tests, while a survey questionnaire provided insights into students' perceptions of the software's usability, engagement levels, and educational value. Key research questions included assessing the relationship between GeoGebra use and academic performance, understanding the correlation between students' perceptions and learning outcomes, and evaluating the overall student experience with GeoGebra. Findings reveal that GeoGebra enhances students' ability to visualize trigonometric concepts, supports individualized learning, and fosters collaboration in the classroom. The software's interactive capabilities help mitigate learning deficiencies and misconceptions, promoting a social constructivist environment that improves mathematical comprehension and problem-solving efficiency. Furthermore, students report positive perceptions of GeoGebra's usability and effectiveness in simplifying complex trigonometric ideas. The dissertation contributes to the limited research on integrating technological tools into trigonometry education, offering practical implications for curriculum development and instructional design. By highlighting GeoGebra's role in transforming traditional teaching methods, the study provides valuable insights for educators and policymakers seeking innovative approaches to enhance mathematics education in the 21st century. This research supports leveraging dynamic educational technologies to create equitable and engaging learning environments that cater to diverse student needs. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]