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Spatial generalizations of the properties of the triangle
Šrubař, Jiří ; Karger, Adolf (advisor) ; Boček, Leo (referee) ; Lávička, Miroslav (referee)
TITLE Spatial generalizations of the properties of the triangle AUTHOR Jirˇı' Sřubarˇ SUPERVISOR Prof. RNDr. Adolf Karger, DrSc. DEPARTMENT Department of mathematics education ABSTRACT The present thesis describes various interesting properties of a triangle. The aim is to find and prove similar properties of its spatial generalization - a tetrahedron. Even though both synthetic and computational methods are used for proving spatial relations, synthetic approach is preferred whenever possible. The thesis is divided into two parts. In the first part, the properties of the tetrahedron analogous to the centroid and the orthocenter of the triangle are described. Also, conditions on the existence of the orthocenter of the tetrahedron are derived. Moreover, for tetrahedrons without an orthocenter, the so-called Monge point is introduced as its generalization. In the second part of the thesis, some further properties of the triangle are studied - - the Simson line, the de Longchamps point, the nine-point circle, the Euler line, the Lemoine point, the isodynamic points, the Lemoine axis and the Brocard axis. As the main contribution of the present thesis we define and prove the existence of spatial analogues of the above mentioned properties for the tetrahedron - the de Longchamps point, the twelve-point and...
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Spatial generalizations of the properties of the triangle
Šrubař, Jiří
TITLE Spatial generalizations of the properties of the triangle AUTHOR Jirˇı' Sřubarˇ SUPERVISOR Prof. RNDr. Adolf Karger, DrSc. DEPARTMENT Department of mathematics education ABSTRACT The present thesis describes various interesting properties of a triangle. The aim is to find and prove similar properties of its spatial generalization - a tetrahedron. Even though both synthetic and computational methods are used for proving spatial relations, synthetic approach is preferred whenever possible. The thesis is divided into two parts. In the first part, the properties of the tetrahedron analogous to the centroid and the orthocenter of the triangle are described. Also, conditions on the existence of the orthocenter of the tetrahedron are derived. Moreover, for tetrahedrons without an orthocenter, the so-called Monge point is introduced as its generalization. In the second part of the thesis, some further properties of the triangle are studied - - the Simson line, the de Longchamps point, the nine-point circle, the Euler line, the Lemoine point, the isodynamic points, the Lemoine axis and the Brocard axis. As the main contribution of the present thesis we define and prove the existence of spatial analogues of the above mentioned properties for the tetrahedron - the de Longchamps point, the twelve-point and...
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Samodlážditelné simplexy
Safernová, Zuzana ; Matoušek, Jiří (advisor)
of the Master thesis Reptile simplices Zuzana Safernová In the present work we study tetrahedral k-reptiles. A d-dimensional simplex is called a k- reptile if it can be tiled in k simplices with disjoint interiors that are all congruent and similar to S. For d=2, triangular k-reptiles exist for many values of k and they have been completely characterized. On the other hand, the only simplicial k-reptiles that are known for d>=3 have k=md , where m>=2 (Hill simplices). We prove that for d=3, tetrahedral k-reptiles exist only for k=m3 . This partially confirms the Hertel's conjecture, asserting that the only tetrahedral k-reptiles are the Hill tetrahedra. We conjecture that k = m^d is necessary condition for existence of d-dimensional simplicial k-reptiles, d > 3.
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Cuts of polyhedrons
Borzíková, Žofia ; Bečvář, Jindřich (advisor) ; Šarounová, Alena (referee)
Title: Cuts of polyhedrons Author: Žofia Borzíková Department: Department of Mathematics Education Supervisor: doc. RNDr. Jindřich Bečvář, CSc., Department of Mathematics Education Abstract: The topic of the bachelor thesis is Cross Sections of Polyhedra. The basic principles of constructing such cross sections are shown and explained through illustrative examples of cross sections of solids together with the detailed description of the construction process. Especially, the cross sections of some "common" polyhedra like prism, tetrahedron, pyramid or octahedron are further discussed. The reader should use them to take up with the main issue of constructing cross sections. As an application of the acquired knowledge, the cross sections of other solids like Platonic or Archimedean solids are introduced here. The goal of these examples is to cultivate spatial intelligence for the purpose of constructing cross sections or better understanding of polyhedral in general. The bachelor thesis is a commented set of examples, which can be used as an additional material in the education of mathematics, not only in grammar schools. Keywords: cross sections, cube, cuboid, prism, pyramid, tetrahedron, regular polyhedra, semi-regular polyhedra
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Samodlážditelné simplexy
Safernová, Zuzana ; Matoušek, Jiří (advisor)
of the Master thesis Reptile simplices Zuzana Safernová In the present work we study tetrahedral k-reptiles. A d-dimensional simplex is called a k- reptile if it can be tiled in k simplices with disjoint interiors that are all congruent and similar to S. For d=2, triangular k-reptiles exist for many values of k and they have been completely characterized. On the other hand, the only simplicial k-reptiles that are known for d>=3 have k=md , where m>=2 (Hill simplices). We prove that for d=3, tetrahedral k-reptiles exist only for k=m3 . This partially confirms the Hertel's conjecture, asserting that the only tetrahedral k-reptiles are the Hill tetrahedra. We conjecture that k = m^d is necessary condition for existence of d-dimensional simplicial k-reptiles, d > 3.
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Spatial generalizations of the properties of the triangle
Šrubař, Jiří ; Karger, Adolf (advisor) ; Boček, Leo (referee) ; Lávička, Miroslav (referee)
TITLE Spatial generalizations of the properties of the triangle AUTHOR Jirˇı' Sřubarˇ SUPERVISOR Prof. RNDr. Adolf Karger, DrSc. DEPARTMENT Department of mathematics education ABSTRACT The present thesis describes various interesting properties of a triangle. The aim is to find and prove similar properties of its spatial generalization - a tetrahedron. Even though both synthetic and computational methods are used for proving spatial relations, synthetic approach is preferred whenever possible. The thesis is divided into two parts. In the first part, the properties of the tetrahedron analogous to the centroid and the orthocenter of the triangle are described. Also, conditions on the existence of the orthocenter of the tetrahedron are derived. Moreover, for tetrahedrons without an orthocenter, the so-called Monge point is introduced as its generalization. In the second part of the thesis, some further properties of the triangle are studied - - the Simson line, the de Longchamps point, the nine-point circle, the Euler line, the Lemoine point, the isodynamic points, the Lemoine axis and the Brocard axis. As the main contribution of the present thesis we define and prove the existence of spatial analogues of the above mentioned properties for the tetrahedron - the de Longchamps point, the twelve-point and...
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Spatial generalizations of the properties of the triangle
Šrubař, Jiří
TITLE Spatial generalizations of the properties of the triangle AUTHOR Jirˇı' Sřubarˇ SUPERVISOR Prof. RNDr. Adolf Karger, DrSc. DEPARTMENT Department of mathematics education ABSTRACT The present thesis describes various interesting properties of a triangle. The aim is to find and prove similar properties of its spatial generalization - a tetrahedron. Even though both synthetic and computational methods are used for proving spatial relations, synthetic approach is preferred whenever possible. The thesis is divided into two parts. In the first part, the properties of the tetrahedron analogous to the centroid and the orthocenter of the triangle are described. Also, conditions on the existence of the orthocenter of the tetrahedron are derived. Moreover, for tetrahedrons without an orthocenter, the so-called Monge point is introduced as its generalization. In the second part of the thesis, some further properties of the triangle are studied - - the Simson line, the de Longchamps point, the nine-point circle, the Euler line, the Lemoine point, the isodynamic points, the Lemoine axis and the Brocard axis. As the main contribution of the present thesis we define and prove the existence of spatial analogues of the above mentioned properties for the tetrahedron - the de Longchamps point, the twelve-point and...
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(Semi) regular tetrahedral tilings
Kolcun, Alexej
Triangulation 2D and 3D methods represent an import ant part of numerical modeling process (e.g. FEM). In many applications it is suitable to use triangulati ons with a regular structure. Moreover, decompositi on with a limited number of different types of tetrahedra ena bles to reduce the storage and computational demand s in the whole modeling process. The submitted contribution presents an overview of possible 3D decompositions using one tetrahedron (regular tilings). These decomposit ions are confronted with decompositions using six d ifferent types of tetrahedra (orthogonal structured tilings) . Considering the shape expressivity of particular methods, the paper presents a structure of possible decompositio ns and comparison of storage demands of the used decompositions.
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