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.
The combinatorial structure of trigonometry.