Geometry

The Five Squarable Lunes
Constructing the Heptadecagon
Iterative Isoscelizing
Parabola Through Four Points
Curvature, Intrinsic and Extrinsic
Sphere Packing In Curved Space
Min-Energy Configurations of Electrons On A Sphere
Distinct Point Sets With Same Distances
Generating Functions for Point Set Distances
Curvature of Linear Interpolation
The Helen of Geometers
Gravity Sextant
An Optical Illusion
Platonic Solids and Plato's Theory of Everything
Euclid's Plan and Proposition 6
What Mirrors Do
Volume of n-Spheres and the Gamma Function
Ptolemy's Orbit
The Golden Pentagon
Trisection On A Budget
Apollonius' Tangency Problem
Loci of Equi-angular Points
Heron's Formula and Brahmagupta's Generalization
Heron's Formula for Tetrahedrons
The Orbit of Triangles
Perpendicular Regression Of A Line
Rolling Spheres and Cones
The Lemniscate and Spacetime
Factoring Convex Figures
Smallest Quadrilateral With Distinct Integer Sides
Mean Distance from Vertex to Interior of Plane Figures
Inside a Tetrahedron
Grazing Goats
Old Notes on Curvature
Did Archimedes Know Gauss-Bonnet?
Leaning Ladders
Pent Up Ratios
Thinking Outside the Triangle
Napoleon's Theorem
The Shape of Coincidence
Double Equations from Triangles in Squares
Main Diagonal Passing Through Interior
Distances In Bounded Regions
Embedding Non-Euclidean Within Euclidean Geometry
Archimedes on Spheres and Cylinders
Trees on a Complex Plain
Acute Problem
Quintisecting an Angle
On Gauss' Mountains
Quadrilateral In a Circle
Volume Under a Triangle
Constructible Points and Coverable Points
A Quarky Formula for Volume of Parallelpiped
Piero della Francesca's Tetrahedron Formula
Automedian Triangles
Curled-Up Dimensions
Piano Keys
On Ptolmey's Theorem
A Plane-Tiling Triple Spiral
Do Equal Bisectors Imply Isosceles?
Equation of a Triangle
Highly Heronian Ellipses
No Equilateral Triangles on a Chess Board
Net Area and Green's Theorem
Ringing of the Changes (The Shape of 4!)
Diophantine Geodesic Boxes
Angular Angst
Random Tiling of a Sphere
Zeno's Mice and the Logarithmic Spiral
Path Lengths and Coordinates
The Cube Unfolded
Harmonia Mensurarum
Constant Headings and Rhumb Lines
Enveloping Circular Arcs
Normals From A Point To An Ellipse
Cutting Self-Similar Pentagons
The Tetratorus and Other Multi-Layered Polyhedra
The Curvatures of Hypersurfaces
Menelaus and Ceva
Carnot, Organizer of Transversals
A Septagonal Non-Periodic Tiling