Molina Jiménez, F. E., Coronel Sánchez, M. E. and Casnanzuela Pachucho, I. A. (2019) “Didactic material in the process of teaching triangles”, Espirales Revista Multidisciplinaria de investigación, 3(29), pp. 1–19. doi: 10.31876/er.v3i29.587.