Investigation of middle school mathematics teachers' concept definitions of geometric objects

The aim of this study is to examine how middle school mathematics teachers define conceptsrelated to geometric objects. The study was carriedout with the participationof 99 mathematics teachers who are working in middle schools in three different provinces and their towns of Turkey. The data were collected through a form consisting of sixopen-endedquestions, which were prepared to reveal the knowledge of the participants about the concepts of geometric objects. In analyzing the data, content analysis was used and then, codes were obtained from the data and categories were obtained from the codes. As results of the study, it was seen thatsome of the participants could not define the concepts of geometric objects (prism, pyramid, cone, sphere and cylinder) exactly and that the participants generally drew the square or rectangular shape in the shape drawing, but mostly the verticalstates of the geometric objects.On the otherhand, it was determined that the participants were generally unable to establish the relationship between "prism and cylinder" and "pyramid and cone".It was alsofound that some of the participants considered themselves insufficient to define the concepts related to geometric objects.