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 Ávila in June 2020 (Sánchez, 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 Ávila in June 2020 (Sánchez, 2020).Este trabajo se enmarca en el contexto de los proyectos de innovación educativa dentro de la didáctica específica de las matemáticas en el nivel de Educación Secundaria Obligatoria. En concreto, en este artículo proponemos, y llevamos a la práctica en una experiencia de aula, las líneas metodológicas básicas de lo que se podría denominar una metodología mixta que se basa en los principios y fases del Aprendizaje Basado en Proyectos, pero introduciendo en el proceso, como un elemento intrínsecamente ligado a él, acciones didácticas realizadas según el método de Flipped Classroom. La primera parte del trabajo analiza las dos perspectivas metodológicas citadas y describe las etapas que proponemos seguir para la implementación de la metodología mixta. La parte principal del artículo, por su parte, se ocupa de describir una intervención educativa en la que se implementó una metodología como la descrita, combinada de Aprendizaje Basado en Proyectos con el modelo de Flipped Classroom, en un conjunto de alumnos de 4.º de ESO para trabajar contenidos curriculares de geometría analítica, dentro del área de matemáticas. En la intervención se han empleado instrumentos de pretest-postest para valorar la eficacia de la metodología empleada. Los resultados obtenidos evidencian que se ha logrado un incremento significativo de los conocimientos de los alumnos en el área tratada derivado de la intervención. Los resultados de este artículo están basados en los contenidos presentados por la segunda autora en su Trabajo Fin de Máster de Profesorado de Educación Secundaria en la Universidad Católica de Ávila en junio de 2020 (Sánchez, 2020)
