Development and Validation of TRIBOO: A Supplementary Workbook for Learning Basic Concepts of Trigonometry

This study entitled "Development and Validation of TRIBOO: A Supplementary Workbook for Learning Basic Concepts of Trigonometry" aimed to address the poor proficiency of Grade 12 STEM students in trigonometry.A quasi-experimental design with a one-way pre-test and post-test was employed to assess their proficiency level and evaluate the effectiveness of TRIBOO, a supplementary workbook developed by the researchers.The pre-test results revealed a low mean score of 5.06, indicating a need for intervention.TRIBOO was validated by five experts and received an overall rating of 3.71, indicating it was highly recommended.After using TRIBOO, students' proficiency significantly improved, with a mean score of 10.00 in the post-test.This suggests that TRIBOO is a valuable resource for math teachers to enhance their instructional approach and improve student outcomes in trigonometry.However, further research is needed to explore the longterm impact of TRIBOO and its applicability to different student populations and learning contexts.