Examining 8th grade students' strategies for identifying the similarity of polygons

In this study, it is aimed to determine eighth grade students' strategies for identifying the similarity of polygons and to examine them in depth. An intrinsic case study design, which is one of the qualitative research methods, was used in accordance with this aim. Seven different activities which were developed by the researcher were used as data collection tools. Validity and reliability of the data collection tools were identified in a pilot study. Throughout the instruction, students were given various similar or non-similar polygons for each activity. The activities were implemented to eight students divided into three groups and the teaching process was recorded with video cameras for each group. All activities took six hours in total. According to the research results, the students used the most number of strategies in the activity that the similarity of square and rhombus were examined whereas they used the fewest number of strategies in the activity that the similarity of triangles were examined. The additive strategy, the angle type strategy and the similarity ratio strategy have been the most prominently used strategies. In addition to this, it was observed that students have more difficulty in the activities that they were asked to construct similar polygons compared to the activities of identifying similar or non-similar polygons. At the end of the study, the suggestions were given to researchers by taking the consequence of this study into account.