Vicente, F.W.L. et al. 2025. Why does the trigonometric circle have a radius of 1? solving trigonometric problems in the light of Conceptual Fields Theory . Revista Paranaense de Educação Matemática. 14, 34 (Aug. 2025), 01–21. DOI:https://doi.org/10.33871/rpem.2025.14.34.10401.