Student Number : 8800092K - MSc research report - School of Education - Faculty of Science / This research report explored the strategies which grade 12 learners employ to solve geometric problems. The purpose of this research was to gain an understanding of how grade 12 learners begin to solve geometric problems involving cyclic quadrilateral and tangent theorems. A case study method was used as the main research method. The study employed the van Hiele level’s of geometric thought as a method for categorising learners levels of understanding. Data about the strategies which learners recruit to solve geometric problems were gathered using learner-based tasks, semi-structured interviews and document analysis. From the data gathered, the following patterns emerged: learners incorrect use of theorems to solve geometrical problems; learners base their responses on the visual appearance of the diagram; learners “force “ a solution when one is not available; learners’ views of proof. Each of these aspects is discussed. The report concludes that learners strategies to solving geometric problems are based largely on the manner in which educators approach the solving of geometrical problems.

Made available in DSpace on 2016-04-27T17:13:02Z (GMT). No. of bitstreams: 1 Alessandra Nascimento.pdf: 1945223 bytes, checksum: f6950936e78897c5cfc27568b8cd6159 (MD5) Previous issue date: 2005-07-17 / Made available in DSpace on 2016-08-25T17:25:34Z (GMT). No. of bitstreams: 2 Alessandra Nascimento.pdf.jpg: 2104 bytes, checksum: c4715912a635b5fbde63d2a9b070733f (MD5) Alessandra Nascimento.pdf: 1945223 bytes, checksum: f6950936e78897c5cfc27568b8cd6159 (MD5) Previous issue date: 2005-07-17 / The objective of this study is to construct a trigonometrical table, on the basis of historical surveys of the works of Ptolomeu and other mathematicians of Old Greece, to investigate the appropriation of the meaning of the concepts of the trigonometrical reasons: sine, cosine and tangent, in the rectangular triangle, for students of first year Average education. We look for to answer to the research question: How to teach trigonometry in the rectangular triangle in significant way? E also decurrent questions: Which factors influence the acquisition of such knowledge? How to distanciar the use of Trigonometry in Average Education of mechanization? For in such a way we use the estimated theoreticians of Vygotsky in that if relates to the importance attributed to the social interaction, the language and the simbolizaction in the gradual domain of a conceptual field for the pupils, of the estimated theoreticians of Vergnaud, when dealing with the operations invariants: concept-in-action and theorem-in-action, of its conception, of conceptual field and concept, e also in the model presented for Parzysz for a theoretical picture of the education of geometry, where it detaches four stages of the development of the geometric thought. The results of the experimentation point with respect to an imbalance in Geometry and Algebra. The experimentation showed that despite this, an education of the Trigonometry of the generating rectangular triangle of motivations, including diversified activities, with problems situations, that stimulate thinking, the inquiry and carrying through, contributes so that the pupils construct the meaning of the trigonometrical reasons, besides favoring the argument and modifying some wrong conceptions / O objetivo deste estudo é construir uma tabela trigonométrica, com base em levantamentos históricos dos trabalhos de Ptolomeu e outros matemáticos da Grécia Antiga, para investigar a apropriação do significado dos conceitos das razões trigonométricas: seno, cosseno e tangente, no triângulo retângulo, por estudantes do 1o ano do Ensino Médio. Procuramos responder à questão de pesquisa: Como ensinar trigonometria no triângulo retângulo de maneira significativa? E também questões decorrentes: Quais fatores influenciam a aquisição de tal conhecimento? Como distanciar a utilização da Trigonometria no Ensino Médio da mecanização? Para tanto utilizamos os pressupostos teóricos de Vygotsky no que se refere à importância atribuída à interação social, à linguagem e à simbolização no progressivo domínio de um campo conceitual pelos alunos, dos pressupostos teóricos de Vergnaud, ao tratar dos invariantes operatórios: conceito-em-ação e teorema-em-ação, de sua concepção de campo conceitual e de conceito, e também no modelo apresentado por Parzysz para um quadro teórico do ensino da geometria, onde ele destaca quatro etapas do desenvolvimento do pensamento geométrico. Os resultados da experimentação apontam para uma defasagem em Geometria e em Álgebra. A experimentação mostrou que apesar disso, um ensino da Trigonometria do triângulo retângulo gerador de motivações, incluindo atividades diversificadas, com situações problematizadoras, que estimulem o pensar, a investigação e o realizar, contribui para que os alunos construam o significado das razões trigonométricas, além de favorecer a argumentação e modificar várias concepções errôneas

The subject of teacher competencies or knowledge has been a key issue in mathematics education reform. This study attempts to identify and analyze teacher competencies necessary in the orchestration of a problem-centred approach to dynamic geometry teaching and learning. The advent of dynamic geometry environments into classrooms has placed new demands and expectations on mathematics teachers. In this study the Teacher Development Experiment was used as the main method of investigation. Twenty third-year mathematics major teachers participated in workshop and microteaching sessions involving the use of the Geometer's Sketchpad dynamic geometry software in the teaching and learning of the geometry of triangles and quadrilaterals. Five intersecting categories of teacher competencies were identified: mathematical/geometrical competencies. pedagogical competencies. computer and software competences, language and assessment competencies. / Mathematical Sciences / M. Ed. (Mathematical Education)

The subject of teacher competences or knowledge has been a key issue in mathematics education reform. This study attempts to identify and analyze teacher competences necessary in the orchestration of a problem-centred approach to dynamic geometry teaching and learning. The advent of dynamic geometry environments into classrooms has placed new demands and expectations on mathematics teachers. In this study the Teacher Development Experiment was used as the main method of investigation. Twenty third-year mathematics major teachers participated in workshop and microteaching sessions involving the use of the Geometer’s Sketchpad dynamic geometry software in the teaching and learning of the geometry of triangles and quadrilaterals. Five intersecting categories of teacher competences were identified: mathematical/geometrical competences, pedagogical competences, computer and software competences, language and assessment competencies. / Mathematics Education / M. Ed. (Mathematics Education)