11 papers
Joining Two Pairs of Planar Points by Disjoint Arcs: The Sharp Length Bound
George M. Georgiou
Problem F16 of Croft, Falconer, and Guy asks for the least worst-case length needed to join prescribed pairs of points by pairwise disjoint planar arcs, when the distance within ea…
Congruent Triangular Faces, Reflections Allowed: Universal Realization and the Minimum Face Count in Problem B22
George M. Georgiou
Problem B22 in Unsolved Problems in Geometry asks which triangles occur as the common face of a convex polyhedron, how many copies are needed, and how they may be arranged. We sett…
Five-Point Hyperbolas on Power Curves and Near Lamé-Oval Vertices
George M. Georgiou
Problem A33 of Croft--Falconer--Guy records Reznick's question about infinite plane sets for which every five-point subset determines an ellipse or, respectively, a hyperbola, and…
Reciprocal-Polar Linearization and Two Conic Constructions for the Cone Projection
George M. Georgiou
Let $$ f_R(x)=\frac{x}{1+\norm{x}/R},\qquad R>0, $$ be the radial cone projection of the plane onto the open disk $\DR=\{x:\norm{x}<R\}$. Previous work established the Self-Directr…
Straightedge-and-Compass Constructibility of the Reciprocal--th-Power Law
George M. Georgiou
Given positive lengths and and a positive integer , let be determined by We prove that a single finite unmarked-stra…
The Cone Projection : Geometric structure and the Self-Directrix Theorem
George M. Georgiou
The cone projection is a radial homeomorphism from onto the open disk of radius , obtained by an elementary cone-and-perpendicular constr…