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Title: Dragging maintaining symmetry: can it generate the concept of inclusivity as well as a family of shapes?
Authors: Forsythe, Susan K.
First Published: 15-Oct-2015
Publisher: Taylor & Francis (Routledge)
Citation: Research in Mathematics Education, 2015 (In press)
Abstract: This article describes a project using Design Based Research methodology to ascertain whether a pedagogical task based on a dynamic figure designed in a Dynamic Geometry Software (DGS) program could be instrumental in developing students’ geometrical reasoning. A dragging strategy which I have named ‘Dragging Maintaining Symmetry’ (DMS) was shown to be important for the making of mathematical meanings in the context of Dynamic Geometry. In particular, it encouraged students’ development of the concept of inclusive relations between shapes generated from the dynamic figure, especially the rhombus as a special case of the kites. This development was not automatic and in addition to their work with the dynamic figure the students were shown an animation of the figure under DMS. Watching the animation allowed the students to attend to the continuous nature of the changing figure and proved to be the catalyst for moving their reasoning towards perceiving inclusive relations between the rhombus and kite.
DOI Link: 10.1080/14794802.2015.1065757
ISSN: 1479-4802
eISSN: 1754-0178
Version: Post-print
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © 2015 British Society for Research into Learning Mathematics. This is an Accepted Manuscript of an article published by Taylor & Francis in Research in Mathematics Education on 15 October 2015, available online:
Description: The file associated with this record is under an 18-month embargo from publication in accordance with the publisher's self-archiving policy, available at The full text may be available through the publisher links provided above.
Appears in Collections:Published Articles, School of Education

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