Students’ ontogenic obstacle on the topic of triangle and quadrilateral

This research based on the students’ difficulty in solving problem in triangle and quadrilateral topic. The difficulties can be identified from the mistakes made by students when solving triangle and quadrilateral problems. It can be caused because of learning obstacle experienced by the students. The learning obstacle which was described on this research is only focused on ontogenic obstacle. The purpose of this research is to identify the ontogenic obstacle based on the mistakes of the students in topic of triangle and quadrilateral. This research used a qualitative approach. The research was conducted to 25 grade VII students in one of junior high schools in Sumedang and a teacher as participants. Furthermore, the students answered 5 questions in test given and then the researcher interviewed 3 students based on their answers on the test. The researcher analysed the data of this research by using triangulation method from data of students’ answer on the test given, also interview of the teacher and the students. The result of this research showed that the researcher identified the ontogenic obstacles experienced by the students on topic of triangle and quadrilateral. The first ontogenic obstacle is psychological ontogenic obstacle where the student were less interested to the learning process of triangle and quadrilateral topic. The second ontogenic obstacle is instrumental ontogenic obstacle where the student were mistaken to recognize the guideline line on the picture given, and the last ontogenic obstacle is conceptual ontogenic obstacle where the student did not understand the topic of quadrilateral well based on the learning experience of the student in measuring length and area.