Undergraduates’ proof construction character on geometry

Constructing a mathematical proof is very challenging for many mathematics students. Many of them having difficulties when doing such construction. This study aimed to investigate and categorize mathematics undergraduate students’ character when construct formal proof on geometry. The data were obtained within 2 phases. Participants were asked to write down the proof of proving-question in phase 1 and they were interviewed to deepen the information in phase 2. The results show that just two of eight students who correctly answer the question and are categorized as students in Quadrant I character. None of participants who is categorized in Quadrant II and two of them are categorized in Quadrant III. Most of the participants (5 out of 8) are categorized in Quadrant IV. Thus, means that most participants have wrong proof-structure and poor connection between concept image and concept definition.