Epistemological obstacle on the topic of triangle and quadrilateral

摘要

This study aims to investigate how students understanding of triangle and quadrilateral topic. It was part of didactical design research which was conducted on 33 students who have learned about triangle and quadrilateral. Data were collected through the students answers and interview related to how students find solution to problems on the topic of geometry. The result found of the type of learning obstacle that is epistemological obstacle that impact on the concept error in solving the problem. The limited knowledge of students when understanding the basic topics in identify the elements and the properties of a plane figure is a factor causing the emergence of common errors in the topic of geometry.