Abstract
This study analyzes the didactic implementation of the dihedral group as a core object of algebraic structure, approached from the Ontosemiotic Framework of mathematical knowledge (Godino et al., 2007). Conducted with 33 undergraduate students enrolled in a teacher education program in Mathematics and Physics, the intervention involved the design and application of a two-session instructional sequence grounded in the coordination of perceptual, symbolic, and structural representations. Through the use of manipulatives (regular polygons made of foam), Cayley tables, permutation notation, and cyclic diagrams, students progressively transitioned from a perceptual understanding of symmetry to the formal construction of group properties. The analysis of student artifacts revealed significant epistemic-semiotic configurations, including the emergence of invariants, generalization patterns, and discursive structures consistent with institutional mathematical meaning. This work evidences the potential of the Ontosemiotic Approach to articulate concrete, semiotic, and epistemological dimensions in the formation of prospective mathematics teachers