The specialization of mathematic teachers’ knowledge is perceived from the Mathematics Teacher’s Specialised Knowledge and Interpretative Knowledge perspectives. To better understand the content of such knowledge we seek to answer the following question: what Interpretive Knowledge reveals mathematics teachers participating in a professional development context, and how the level of such knowledge relates to the levels of teachers’ Mathematical Specialised Knowledge in the scope of translation and rotation? For doing so, Interpretative Tasks were implemented in a teacher education context with 15 mathematics teachers aimed at accessing and developing teachers Interpretative and Specialised knowledge. The results pinpoint an intertwined relationship between the levels of this knowledge, in which a way that the interpretation that the teacher makes is impacted by the content of his/her Specialised Knowledge.