Ogbonnaya, Ugorji2025-06-302025-06-302025-09-262024-12-18*S2025http://hdl.handle.net/2263/103055https://doi.org/10.25403/UPresearchdata.29424047.v1Thesis (PhD)--University of Pretoria, 2024.ABSTRACT Euclidean geometry has been highlighted as a topic in mathematics that presents challenges to many secondary school students. Since teachers and students rely on textbooks for teaching and learning, the students' challenges could be linked to poor opportunities to learn Euclidean geometry in the textbooks. This study investigated the opportunities to learn Euclidean geometry in secondary school mathematics textbooks. In particular, the study examined the extent to which the content of Euclidean geometry addresses the Curriculum and Assessment Policy Statements content for Grades 10-12. It also investigated the Euclidean geometry learning opportunities included in tasks regarding the nature of tasks and levels of geometric thinking. In addition, the study examined the nature of tasks and the levels of geometric thinking of the tasks in the textbooks. Lastly, it examined the Euclidean geometry learning opportunities in the textbook tasks regarding the forms of representation, contextual features and forms of answers. The study employed a qualitative case study research approach where textbook content analysis technique was used to collect data from three purposefully selected textbook series. All the Euclidean geometry tasks in the three textbook series were analysed using a 6D analytical framework. The dimensions of the textbook tasks analysis were content coverage, type of required mathematical activity, geometric thinking levels involved, forms of representation, contextual features, and the answer forms. The findings of the study indicated that the textbooks do not provide sufficient Euclidean geometry learning opportunities. The content coverage in the textbooks did not align with the prescribed curriculum document, as they did not completely address Euclidean geometry as prescribed in the curriculum. The analysis also revealed that the tasks do not have diverse types, the types of tasks in textbooks are dominated by one mathematical activity (calculation and operation), one geometric thinking level (informal deduction), one representation form (combined form), one context type (non-application) and one answer form (closed answer). Tasks focusing on representation and modelling, interpretation, visual, analytical and rigour, visual form, pure mathematical form, application tasks and open-ended type tasks were found to be rare. The findings have important implications for textbook writers to use the different types of textbook tasks to provide students with better Euclidean geometry learning opportunities. Teachers may need to supplement the textbook with additional resources that offer opportunities for students to engage with Euclidean geometry concepts. Keywords: Answer forms, content coverage, contextual forms, Euclidean geometry, geometric thinking levels, mathematics textbooks, nature of tasks, Opportunity to Learn, representation form, Tasksen© 2024 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.UCTDThesisu99308992