This study explores the effectiveness of the GeoGebra on Grade 12 students' success in making associations between the representations of trigonometric functions and the interpretation of graphs. A technology-oriented classroom is a commanding and accommodating tool in mathematics instruction in understanding mathematical concepts. A non-equivalent control-group pre-test and post-test quasi-experimental design was used. The study sample consisted of seventy-three Grade 12 students enrolled in Science, Technology, Engineering and Mathematics (STEM) from different schools of the Hadiya zone. The research instrument used was a trigonometric representation ability test. The data analysis used was based on the t-test, ANOVA, and the mean of achievement indicators. The results indicated a statistically significant difference between the overall score mean achievements of experimental groups A and B and the control group on making associations between representations of trigonometric functions, and interpretations of the representations of the trigonometric functions, in the indulgence of both experimental groups. As the association between the trigonometric function representations and an interpretation of graphs of the functions are major challenges to many students in the mathematics field, integration of technology into the teaching of the subject simplifies the life of students. We therefore strongly recommend that teachers integrate GeoGebra with the teaching of trigonometric functions and mathematics in general. Hence, we also recommend that teacher training institutions should include courses on how to use dynamics software applications to teach mathematics in teacher-training programmes. This recommendation will also be applied in Wachemo University, Ethiopia, where the research occurred.