Application of Lesson Study on Circle Material to Improve the Quality of Mathematics Instruction in Grade XI

Improving the quality of mathematics learning is an important step to ensure students can understand mathematical concepts deeply. This study aims to improve the quality of mathematics learning on circle material in class XI through the application of lesson study. This research is a qualitative research that aims to explore and understand the process of implementing lesson study in mathematics learning with the stages of plan, do and see. In the first cycle, the lesson study was applied with Problem Based Learning (PBL) model with LKPD and PowerPoint media. The second cycle used Think Pair Share (TPS) model with the support of wordwall interactive media. The results of this study showed that lesson study effectively increased student participation and learning quality through method innovation, interactive media utilization, and improved time management. Therefore, lesson study can be used as an effort to improve the quality of mathematics learning, especially on circle material.