This study investigated the effect of a paper folding activity prepared to develop the sixth-grade students' concept definitions and images of parallelism and perpendicularity concepts. The study also examined how the concept definition and images changed after the paper folding activity. A combination of quantitative and qualitative methods was…

The present study examines secondary school students' geometrical figure apprehension based on Duval's theoretical framework regarding perceptual, operative, and discursive apprehension. The aim is to explore the cognitive structure of the geometrical figure apprehension dimensions (operative, discursive, and perceptual) in three grades of…