The purpose of this paper is to investigate some of the properties of convex sets in the plane through synthetic geometry.

Submitted by MARCIA ROVADOSCHI (marciar@unifra.br) on 2018-08-20T17:09:11Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_NadiaRobertaQuainiBresolin.pdf: 2962274 bytes, checksum: 08e27819aea17dfb2d8c955d8761f265 (MD5) / Made available in DSpace on 2018-08-20T17:09:11Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_NadiaRobertaQuainiBresolin.pdf: 2962274 bytes, checksum: 08e27819aea17dfb2d8c955d8761f265 (MD5) Previous issue date: 2016-11-30 / This research aimed to investigate how the GeoGebra software can provide the development of creative, intuitive and visual abilities in the statement of theorems of synthetic geometry. The research was carried out with five students of the first year of high school in a state school of Rio Grande do Sul. This is a qualitative research carried out in the computer lab; data collection was obtained through the records of the constructions carried out by students and analyzed existing protocols in the software itself. The investigative activities, developed in workshop mode, consisted of four specific theorems of plane geometry, chosen at random and feasible to be offered to students of elementary school. The research results showed that the activities provided through the GeoGebra software, the development of creativity, the use of intuitive thinking and visualization as a way of analyzing the operation of ideas in the formulation of conjectures, which contributed to the construction of theorems, providing meaningful learning. Also, it indicates synthetic geometry as a way to perform logical statements of theorems, developing reasoning skills and justifications. In turn, the results showed that the use of GeoGebra software, used in construction, was key to achieving the goals in the research. / Este trabalho de pesquisa teve como objetivo investigar de que forma o software GeoGebra pode proporcionar o desenvolvimento de habilidades criativas, intuitivas e visuais na demonstração de teoremas de Geometria Sintética. A investigação foi realizada com cinco alunas do primeiro ano do Ensino Médio de uma Escola Estadual do Rio Grande do Sul. Trata-se de uma pesquisa de cunho qualitativo realizada em laboratório de informática; a coleta de dados foi obtida pelos registros das construções realizadas pelas estudantes e analisados os protocolos existentes no próprio software. As atividades investigativas, desenvolvidas na modalidade de oficina, consistiram de quatro teoremas específicos de Geometria Plana, escolhidos aleatoriamente e viáveis de serem propostos aos estudantes da escola básica. Os resultados da investigação demonstraram que as atividades propostas oportunizaram, por meio do software GeoGebra, o desenvolvimento da criatividade, o uso do pensamento intuitivo e a visualização como forma de analisar a exploração de ideias na formulação de conjecturas, o que contribuiu para a construção dos teoremas, propiciando uma aprendizagem significativa. Além disso, indica Geometria Sintética como uma forma de realizar demonstrações lógicas de teoremas, desenvolvendo habilidades de argumentação e justificativas. Por sua vez, os resultados mostraram que o uso do software GeoGebra, utilizado nas construções, foi fundamental para atingir os objetivos propostos na pesquisa.

A synthetic approach to the construction of projective geometry, its methods and selected results are given in the proposed thesis. The main historical drawbacks of the original proof of Chasles's theorem for non-developable ruled surfaces and von Staudt's formalization of projective geometry are commented. The corre- sponding theoretical background is elaborated on visual demonstrations with the accent to interrelations of classical synthetic, axiomatic and analytic points of view. Synthetic methods of projective geometry and their mixture with analytic methods are described on examples including numerous alternative proofs and generalizations of some theorems. A method of four-dimensional visualization is introduced in details. Elementary constructions of images of points, lines, planes and 3-spaces are followed by models of polychora, their sections and shadows. Chasles's theorem is proven for non-developable ruled quadrics on synthetic vi- sualizations, then generalized and proven within the pure projective framework for algebraic surfaces. The synthetic classification of regular quadrics is derived from descriptive geometry constructions of sections of four-dimensional cones and analytically verified in the projective extension of the real space. An integral part of the thesis is a...

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In the present work, we tried to investigate the conics in the synthetic, analytical and projective contexts, as well as to know some applications and properties of these curves. In the synthetic approach, it was emphasized a lithe of the historical aspects, the works made by Apollonius and Dandelin, a characterization for tangent and normal lines and re ecting properties. In the analytical approach, the Cartesian, polar and parametric equations were described, as well as the applications in the Kepler Laws. In the projective approach, the concepts of projective plane, projective point, projective line and projective applications were used to give meaning to the conic in the projective universe, in addition the Theorews of Pascal and Brianchon were demonstrated. / No presente trabalho, procurou-se investigar as cônicas nos contextos sintético, analítico e projetivo, bem como conhecer algumas aplicações e propriedades dessas curvas. Na abordagem sintética, foram enfatizados um pouco do aspecto histórico, os trabalhos feitos por Apolônio e Dandelin, uma caracterização para retas tangentes e normais e as propriedades refletoras. Na abordagem analítica, foram descritas as equações cartesianas, polares e paramétricas, como também as aplicações nas Leis de Kepler. Na abordagem projetiva, foram trabalhados os conceitos de plano projetivo, ponto projetivo, reta projetiva e aplicações projetivas para dar significado as cônicas no universo projetivo, além disso foram demonstrados os teoremas de Pascal e Brianchon. / São Cristóvão, SE

The diploma thesis deals with metric tasks in space, using synthetic and analytical geometry. In addition to explaining the different approaches, there is a set of examples to practice. The solution of the examples is part of the Portal of High School Mathematics (Portál středoškolské matematiky), where we can and analytical solutions, synthetic numerical solutions and synthetic constructional solutions.

The first International Congress of Mathematicians (ICM) was held in Zurich in 1897, setting the standards for all future ICMs. Whilst giving an overview of the congress itself, this thesis focuses on the Swiss organisers, who were predominantly university professors and secondary school teachers. As this thesis aims to offer some insight into their lives, it includes their biographies, highlighting their individual contributions to the congress. Furthermore, it explains why Zurich was chosen as the first host city and how the committee proceeded with the congress organisation. Two of the main organisers were the Swiss geometers Carl Friedrich Geiser (1843-1934) and Ferdinand Rudio (1856-1929). In addition to the congress, they also made valuable contributions to mathematical education, and in Rudio's case, the history of mathematics. Therefore, this thesis focuses primarily on these two mathematicians. As for Geiser, the relationship to his great-uncle Jakob Steiner is explained in more detail. Furthermore, his contributions to the administration of the Swiss Federal Institute of Technology are summarised. Due to the overarching theme of mathematical education and collaborations in this thesis, Geiser's schoolbook "Einleitung in die synthetische Geometrie" is considered in more detail and Geiser's methods are highlighted. A selection of Rudio's contributions to the history of mathematics is studied as well. His book "Archimedes, Huygens, Lambert, Legendre" is analysed and compared to E W Hobson's treatise "Squaring the Circle". Furthermore, Rudio's papers relating to the commentary of Simplicius on quadratures by Antiphon and Hippocrates are considered, focusing on Rudio's translation of the commentary and on "Die Möndchen des Hippokrates". The thesis concludes with an analysis of Rudio's popular lectures "Leonhard Euler" and "Über den Antheil der mathematischen Wissenschaften an der Kultur der Renaissance", which are prime examples of his approach to the history of mathematics.