Development of a Local Instruction Theory for Trigonometric Ratios

Some students find trigonometric ratios challenging. Research on the application of Local Instruction Theory (LIT) in trigonometry is limited, particularly in secondary school understanding of trigonometric ratios. This study aims to develop an LIT for trigonometric ratios using Realistic Mathematics Education (RME). The re-searcher designed a learning pathway to help students grasp the fundamental concepts of trigonometric ra-tios. The study employs a research design methodology, developing a Hypothetical Learning Trajectory (HLT) to improve students' understanding. The development of LIT for Trigonometric Ratios follows three stages: initial design, teaching experiments, and retrospective analysis. Students demonstrated the ability to under-stand trigonometric ratios through the learning process. The findings suggest that the use of LIT-based in-structional materials, incorporating RME principles, significantly enhances students' conceptual understand-ing of trigonometric ratios in high school.
Keywords: Local Instruction Theory; Hypothetical Learning Trajectory; Trigonometric Ratios; RME