<jats:p>In the last three decades, the application of TUIs (tangible user interfaces) in education has demonstrated its positive influence on performance and learning of students. At Universidad del Desarrollo in Chile, monitoring of diagnostic tests over time evidences difficulties and challenges in the teaching-learning of trigonometry in first-year Engineering education. This study consisted in designing and validating a tangible interface to learn trigonometry in the classroom setting. The methodology used was a quasi-experiment with first-year students from the Schools of Design and Engineering at Universidad del Desarrollo in Chile. Principles of the theory of Embodied Cognition and Blended Interaction were applied to model an intuitive, collaborative and meaningful learning experience. During the design process, three Intermediate Models were tested with several types of users, and two Prototypes were tested with an experimental group. User-testing highly contributed to the design of the interaction experience and the interface, progressively defining the functional and pedagogical aspects. Comparative analysis of Pre and Post-Test results, demonstrate that students’ performance increased by 37.1% after two sessions using the interface.</jats:p>
