Formal Deductive Proof in Geometry and its Implication in Teaching Process

Mathematical researchers and cognitive psychology focused on several principal reasons based on difficulties of student in deductive proof solving geometry problem. Literatures about geometry problems widely reveal two reasons knowing the difficulties. First, a larger number dont possess the required content knowledge. Second, properties of deductive proof different from most of others mathematical problems. Since, this problem is non-algorithmic, content knowledge is very important, but it is not enough. Thus, almost all problems were not understood by students, therefore they required greater instructional support during the solving process.