Didactic Obstacles in Trigonometric Ratios: Insights into Students’ Mathematical Understanding. Riemann: Research of Mathematics and Mathematics Education, [S. l.], v. 8, n. 1, p. 68–85, 2026. DOI: 10.38114/riemann.v8i1.166. Disponível em: https://journal.sanagustin.ac.id/index.php/reimann/article/view/166.. Acesso em: 12 may. 2026.