[en] This work is part of the educational innovation projects within the specific didactics of mathematics at the Compulsory Secondary Education level. Specifically, in this paper we propose, and put into practice in a classroom experience, the basic methodological lines of what could be called a mixed methodology based on the principles and phases of Project-Based Learning, but introducing into the process, as an element intrinsically linked to it, didactic actions carried out according to the Flipped Classroom method. The first part of the paper analyses the two methodological perspectives mentioned above and describes the stages we propose to follow for the implementation of the mixed methodology. The main part of the paper, for its part, deals with describing an educational intervention in which a methodology such as the one described, combined Project-Based Learning with the Flipped Classroom model, was implemented in a group of 4th year ESO students to work on curricular contents of analytical geometry, within the area of mathematics. In the intervention, pretest-postest instruments have been used to evaluate the effectiveness of the methodology employed. The results obtained show that a significant increase in the students' knowledge in the area treated has been achieved as a result of the intervention. The results contained in this paper are based in the contents presented by the second author in her Final Project for the Master's Degree in Secondary Education Teaching at the Catholic University of ?vila in June 2020 (S?nchez, 2020)./nThis work is part of the educational innovation projects within the specific didactics of mathematics at the compulsory secondary education level. Specifically, in this paper we propose, and put into practice in a classroom experience, the basic methodological lines of what could be called a mixed methodology based on the principles and phases of Project-Based Learning, but introducing into the process, as an element intrinsically linked to it, didactic actions carried out according to the Flipped Classroom method. The first part of the paper analyses the two methodological perspectives mentioned above and describes the stages we propose to follow for the implementation of the mixed methodology. The main part of the paper, for its part, deals with describing an educational intervention in which a methodology such as the one described, combined Project-Based Learning with the Flipped Classroom model, was implemented in a group of 4th year ESO students to work on curricular contents of analytical geometry, within the area of mathematics. In the intervention, pretest-posttest instruments have been used to evaluate the effectiveness of the methodology employed. The results obtained show that a significant increase in the students' knowledge in the area treated has been achieved as a result of the intervention. The results contained in this paper are based in the contents presented by the second author in her Final Project for the Master's Degree in Secondary Education Teaching at the Catholic University of ?vila in June 2020 (S?nchez, 2020).

[es] Este trabajo se enmarca en el contexto de los proyectos de innovaci?n educativa dentro de la did?ctica espec?fica de las matem?ticas en el nivel de Educaci?n Secundaria Obligatoria. En concreto, en este art?culo proponemos, y llevamos a la pr?ctica en una experiencia de aula, las l?neas metodol?gicas b?sicas de lo que se podr?a denominar una metodolog?a mixta que se basa en los principios y fases del Aprendizaje Basado en Proyectos, pero introduciendo en el proceso, como un elemento intr?nsecamente ligado a ?l, acciones did?cticas realizadas seg?n el m?todo de Flipped Classroom. La primera parte del trabajo analiza las dos perspectivas metodol?gicas citadas y describe las etapas que proponemos seguir para la implementaci?n de la metodolog?a mixta. La parte principal del art?culo, por su parte, se ocupa de describir una intervenci?n educativa en la que se implement? una metodolog?a como la descrita, combinada de Aprendizaje Basado en Proyectos con el modelo de Flipped Classroom, en un conjunto de alumnos de 4.? de ESO para trabajar contenidos curriculares de geometr?a anal?tica, dentro del ?rea de matem?ticas. En la intervenci?n se han empleado instrumentos de pretest-postest para valorar la eficacia de la metodolog?a empleada. Los resultados obtenidos evidencian que se ha logrado un incremento significativo de los conocimientos de los alumnos en el ?rea tratada derivado de la intervenci?n. Los resultados de este art?culo est?n basados en los contenidos presentados por la segunda autora en su Trabajo Fin de M?ster de Profesorado de Educaci?n Secundaria en la Universidad Cat?lica de ?vila en junio de 2020 (S?nchez, 2020).