Learning Starts with a Question Mathematics Education pemahaman konsep matematika understanding of mathematical concepts Active Knowledge Sharing learning model Descriptive Analysis Kemampuan Pemecahan Masalah Materi Bangun Ruang Mathematical Representation Ability Pendidikan Matematika Penelitian Deskriptif Kuantitatif Two Variable Linear Equation System activeness descriptive quantitative hasil belajar keaktifan learning outcomes material (cubes and cuboid) model pembelajaran Active Knowledge Sharing problem solving abilities