The paper describes the development and analysis of a quantitative study investigating to what extent the potentials of dynamic geometry environments (DGE), in relation to mathematical reasoning competency, are utilized in lower secondary school in Denmark. The study entails a questionnaire, which was developed on the basis of an extensive review that uncovered four potentials of DGE in relation to reasoning competency: feedback; dragging; measuring; tracing. 220 Danish lower secondary mathematics teachers completed the questionnaire. Analysis indicates that the potentials of measuring and dragging are utilized to some degree, feedback to a lesser degree, while tracing is almost non-existent. Furthermore, there are signs that DGE is used as a substitute for the paper and pencil environment to solve tasks that were originally designed for paper and pencil. Possible improvements of praxis are discussed, and the integration of the results in further research is elaborated upon.