This article documents the classroom mathematical practices observed in a collegiate level teacher education course related to the circle topic. The course, which was prepared as design research, utilized a dynamic geometry environment which influenced the type and nature of the evolved mathematical practices. The study uses emergent perspective as the theoretical framework and Toulmin's model of argumentation to analyze social interactions within the classroom. Findings reveal three sequentially emergent mathematical practices that are in increasing order of complexity. The significance of this analysis stems from the fact that it contributes to an emerging body of knowledge on inquiry-based and technology-supported teaching in social contexts for which more research is needed.