Knowledge of mathematics teachers of how to teach 8th graders content of triangles

Study aimed to document the 8th grade math teachers’ knowledge of how to teach the triangles topic, Hashweh’s Model (2005) was accredited for this purpose. The model included the following components: knowledge of the pedagogical content, beliefs about learning and teaching, learners’ characteristics, educational strategies, educational context, learning sources, curriculum, and clarity of the content and philosophy. The (female) teacher whose students obtained the highest degrees in TIMSS (2015), and the (female) teacher whose students obtained the lowest grades in this test were selected for this study. The researcher applied the qualitative method to collect the required data using different tools, such as questionnaire, oral interviews, classroom observations, content test, and document analysis. The results showed that the teachers’ knowledge of how to teach the content varies. The teacher whose students obtained the highest degrees in TIMSS (2015) test did better in all the knowledge aspects: knowledge of the pedagogical content, beliefs about learning and teaching, learners’ characteristics, educational strategies, educational context, learning resources, and curriculum. On the other hand, their knowledge was equal about the educational objectives. Keywords: pedagogical knowledge, constructivism, mathematics performance, teacher classroom practice, TIMSS.