Exploring Grade 12 teachers’ pedagogical content knowledge of Similarity in Euclidean geometry

Abstract

Studies show that Euclidean geometry is a section of school mathematics that takes more work to learn and teach in South Africa. Learners need to do better in Grade 12 matric examinations. The role of teachers in the learning and teaching process is critical for learners' success. This study explored Grade 12 teachers' Pedagogical Content Knowledge (PCK) about similarity in Euclidean geometry, as their depth in a subject specific PCK influences their classroom practices. Issues raised in the Grade 12 NSC diagnostic reports of the five consecutive years, 2017 to 2021, formed a basis for what to pursue. A qualitative research method was followed to establish the teachers' PCK via their ability to identify and correct the misconceptions and errors of the Grade 12 learners using written work of similarity concepts in Euclidean geometry. Eight secondary school teachers who offer mathematics in the Gauteng North district in the Gauteng province were purposively sampled and participated in the study. The study's findings revealed that with some of the teachers, their PCK depth of similarity in Euclidean geometry is lacking in identifying and addressing learner misconceptions and errors. Their challenges are similar to those of learners, as reported in the NSC diagnostic reports. These findings have several implications. This highlights the greater challenge of breaking the cycle of learners' poor performance in Euclidean geometry in South African schools. Secondly, the study's outcomes identify where one can intervene in improving the teachers' PCK. Lastly, it poses the challenge of revisiting the school curriculum by the Department of Basic Education and for South African tertiary institutions that train secondary school teachers to also re-visit their training programmes.