@inbook {454, title = {Winkel in der Sekundarstufe I {\textendash} Sch{\"u}lervorstellungen erforschen}, booktitle = {Geometrie zwischen Grundbegriffen und Grundvorstellungen}, year = {2015}, pages = {29-42}, publisher = {Springer Verlag}, organization = {Springer Verlag}, address = {Berlin}, url = {http://link.springer.com/book/10.1007/978-3-658-06835-6}, author = {Christian Dohrmann and Ana Kuzle}, editor = {Andreas Filler and Anselm Lambert} }