The present paper describes a dynamic investigation of polygons obtained by reflecting an arbitrary point located inside or outside a given polygon through the midpoints of its sides. The activity was based on hypothesizing on the shape of the reflection polygon that would be obtained, testing the hypotheses using dynamic software, and finding a…

This study investigated the concept images of blind students about the polygon concept. For this purpose, four open-ended questions were asked to five blind middle school students. During the interviews, geometric shapes were presented with raised-line materials and blind students were given opportunities to construct geometric shapes with…

In our study, we looked for an answer to the research question "How prospective teachers comprehend the concept of a plane angle and what kind of variation there is between the conceptions? The study shows that the prospective teachers interpret the concept "plane angle" which in principle is familiar to everybody in many different…

Secondary geometry students were tested for van Hiele level of thinking, geometry knowledge and achievement, and proof-writing achievement. Proof-writing achievement correlated significantly with van Hiele level entering geometry knowledge and geometry achievement. The predictive validity of the van Hiele model was supported. (Author/DC)

Secondary school geometry students have been found to have misconceptions concerning parallel lines. Correctional teaching programs did not seem effective in changing these misconceptions. This research describes an attempt to use teaching strategies which take into account current learning theory and which encourages students to be actively…