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Preservice Teachers’ Creation of Dynamic Geometry Sketches to Understand Trigonometric Relationships

, Boston University, United States ; , University of Idaho, United States ; , Kennesaw State University, United States

CITE Journal Volume 18, Number 3, ISSN 1528-5804 Publisher: Society for Information Technology & Teacher Education, Waynesville, NC USA


Dynamic geometry software can help teachers highlight mathematical relationships in ways not possible with static diagrams. However, these opportunities are mediated by teachers’ abilities to construct sketches that focus users’ attention on the desired variant or invariant relationships. This paper looks at two cohorts of preservice secondary mathematics teachers and their attempts to build dynamic geometry sketches that highlighted the trigonometric relationship between the angle and slope of a line on the coordinate plane. We identify common challenges in the construction of these sketches and present examples for readers to interact with that highlight these issues. Lastly, we discuss ways that mathematics teacher educators can help beginning teachers understand common pitfalls in the building of dynamic geometry sketches, which can cause sketches not to operate as intended.


Brakoniecki, A., Amador, J. & Glassmeyer, D. (2018). Preservice Teachers’ Creation of Dynamic Geometry Sketches to Understand Trigonometric Relationships. Contemporary Issues in Technology and Teacher Education, 18(3), 494-507. Waynesville, NC USA: Society for Information Technology & Teacher Education. Retrieved March 20, 2019 from .

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