Analysis of Grade VIII Students' Geometric Thinking Ability in Flat Surface Construction Material Based on Van Hiele's Theory

Abstract

Geometric thinking ability is a process carried out by students to obtain information, then from that information, they draw conclusions to solve problems related to geometry. The thinking process of each student is different and not always the same between one student and another. Therefore, to determine geometric thinking ability, we can look at the students' ability to pass through the stages of geometric thinking based on Van Hiele's Theory. These stages are level 0 (visualization), level 1 (analysis), level 2 (informal deduction), level 3 (deduction), and level 4 (rigor). The subjects in this study were students in class VIII at Miftahul Ulum As-Sholchah Islamic Junior High School in Warungdowo, Pasuruan who had already learned the material on flat-sided shapes. There were three subjects who had geometric thinking abilities, and they were selected using purposive sampling. This study aims to explore the geometric thinking abilities of eighth-grade students in flat-sided spatial figures based on Van Hiele's Theory. The method used in this study is an exploratory qualitative research method with data collection techniques using tests and interviews. The results of this study indicate that the geometric thinking abilities of eighth- grade students in flat-sided solid geometry material based on Van Hiele's Theory are at level 0 (visualization), level 1 (analysis), level 2 (informal deduction), and level 3 (deduction), but none of the students are at level 4 (rigor).