Students' geometric reasoning proficiency reviewed through Van Hiele's 5 levels of geometry

Abstract

This study aims to find out the effectiveness students' geometric reasoning based on the van Hiele's 5 levels of geometry. In the analysis, researcher is applied as a method; the combination of qualitative and quantitative methods. The quantitative method is obtained by assigning geometric reasoning to the student, while the qualitative method is obtained from the interview result. The data analysis is performed by applying SPSS (Statistical Package for the Social Sciences) with t-test. The increase is illustrated byvan Hiele's geometry post-test results which go up in comparison with the previous level. The geometry level of students mounts to a higher one. The levels discussed are van Hiele's 5 levels, which are level (0) (visualization), level 1 (analysis), level 2 (informal deduction), level 3 (deduction), and level 4 (rigor). In the initial stage, the subject was tested through van Hiele's geometry test, and the indication of levels was checked as well. Next stage would be performing validated.. The results of the research show that the learning models through the class are more effective in increasing students' geometric level. Subsequently, it is expected that with the result of this analysis, teachers can upgrade students' geometric level, reviewed from other geometry theories.