PROFIL ABSTRAKSI MATEMATIS SISWA SMP DALAM MEMBENTUK KONSEP SEGITIGA

Abstract. This study aims to describe the profile of junior high school students' mathematical
abstraction in forming the concept of triangles in terms of high, medium, and low levels of
mathematical ability, based on the aspects of RBC+C, namely recognizing, building-with,
constructing, and consolidation. This study uses a descriptive qualitative approach with three
seventh-grade students as subjects, one student each with high, medium, and low mathematical
ability, selected based on the results of a mathematical ability test. Data were collected through
triangle abstraction assignments and interviews, then analyzed using the Miles and Huberman
model which includes data condensation, data presentation, and drawing and verifying
conclusions. The results showed that students with high mathematical ability were able to pass
all aspects of RBC+C optimally, students with medium ability were able to reach all aspects but
not optimally, while students with low ability experienced limitations in almost all aspects of
mathematical abstraction, especially in the aspects of building-with, constructing, and
consolidation. Thus, the level of students' mathematical ability significantly influences the quality
of the mathematical abstraction process in forming the concept of triangles.
Keywords: Mathematical Abstraction, Concept, Triangle, Mathematical Ability, RBC+C