
06451940
a
2015d.00633
Jones, Keith
Fujita, Taro
Characterising triangle congruency in lower secondary school: the case of Japan.
Ubuz, Behiye (ed.) et al., CERME 8. Proceedings of the eigth congress of the European Society of Research in Mathematics Education, Antalya, Turkey, February 610, 2013. Ankara: Middle East Technical University (ISBN 9789754293159). 655664 (2013).
2013
Ankara: Middle East Technical University
EN
G43
triangles
geometry
congruency
textbooks
secondary school
Summary: Congruence, and triangle congruence in particular, is generally taken to be a key topic in school geometry. This is because the three conditions of congruent triangles can be used when proving geometrical theorems and also because triangle congruency relates to the idea of mathematical similarity via similar triangles. Despite the role of congruency, and of congruent triangles in particular, there appears to be limited research on the topic. In this paper we report on the approach to triangle congruency in textbooks used in lower secondary school in Japan specifically in grade 8 (students aged 1314). We found that the modicum of practical tasks entailed various conceptions (measuring, transformations, etc.) whereas the proof problems which predominated expected students to utilise corresponding parts and known facts.