The primary objective of this study was to create educational resources rooted in the indigenous knowledge of North Sumatra. Employing the 4-D development model, the research utilized both qualitative and quantitative analyses. The outcome was the production of a geometry learning tool, subjected to assessments of validity, practicality, and efficacy. The tool's testing revealed notable improvements in students' mathematical problem-solving skills between Trial I and Trial II, with indicators displaying an average increase of 0.35%, 3.99%, 16.22%, and 8.32%, respectively.