Analisis Berpikir Siswa dalam Memecahkan Masalah Segiempat Berdasarkan Level van Hiele

The reason behind this research is the low mathematical ability of the students in geometry. They think that geometry is difficult to comprehend, so that we need a lesson from the teacher in order to make students interested in studying geometry. In order to create interesting learning, teachers need to see students' thinking. Therefore, this research aims to determine students’ thinking ability in solving quadrilateral using Polya’s problem solving steps associated with level descriptors of Van Hiele. This research employed qualitative descriptive study. The subjects of this research were 2 students from each level of visualization, analysis, informal deduction, and 1 student from level of rigor. The initial step of this research was determining the research subject by administering a test, then proceeded by giving a geometry practice test and interviews. The results showed that the students at the visualization and informal deduction both met the indicators of planning, solving, and explaining problems coherently, students at the level of informal deduction also fulfilled the indicators involving previously acquired knowledge to solve problems, the students at the analys level could not fulfill the indicators of analys level, and the students at the rigor level fulfilled one indicator which was using logic in the step of implementing plan.