Systeme halbkonzentrischer Kreise der euklidischen Ebene im komplexen Gebiet.
Tangent segments in Minkowski planes.
Tangential Symmetries of Planar Curves and Space Curves
Tečny dvou kruhů
Tétraèdre dont les six arêtes sont tangentes à une même sphère
The isogonal sponges on the cubic lattice.
The additivity of the volume and Sperner's lemma
The algebra of polytopes in affine spaces.
The application of Pluecker’s line-geometry to the study of polar properties of quadrics
The Banach-Tarski paradox for the hyperbolic plane
The Banach-Tarski paradox for the hyperbolic plane (II)
The second author found a gap in the proof of the main theorem in [J. Mycielski, Fund. Math. 132 (1989), 143-149]. Here we fill that gap and add some remarks about the geometry of the hyperbolic plane ℍ².
The Beckman-Quarles theorem for mappings from to .
The best constant for a geometric inequality.
The best constant for an algebraic inequality.
The best constants for a double inequality in a triangle.
The Betten-Walker spread and Cayley's ruled cubic surface.
The Boundary at Infinity of a Rough CAT(0) Space
We develop the boundary theory of rough CAT(0) spaces, a class of length spaces that contains both Gromov hyperbolic length spaces and CAT(0) spaces. The resulting theory generalizes the common features of the Gromov boundary of a Gromov hyperbolic length space and the ideal boundary of a complete CAT(0) space. It is not assumed that the spaces are geodesic or proper
The Cayley–Menger determinant is irreducible for .
The classification of compact hyperbolic Coxeter d-polytopes with d + 2 facets.
The Classification of Quasi-Regular Polyhedra of Genus 2.