Some Unmotivated Cabri 3D Constr

Some Unmotivated Cabri 3D Constructions

Jen-chung Chuan

Unmotivated = No Algebra

Unmotivated = Not Found in Euclid

Unmotivated = Discovered Accidentally

Unmotivated = Not Routine

Unmotivated = Tailor-Made

Unmotivated = So Short, So Beautiful, So Fun

Construction of a Pentagonal Cupola starting with a Dodecahedron

Smallest Cube Containing a Regular Tetrahedron

Construction of a Triangular Cupola starting with a triangle

Triangular Cupola as Convex Hull of Tetrahedra

Triangular Gyrobicupola as Convex Hull of Tetrahedra

Square Gyrobicupola as Convex Hull of Six Squares

Square Cupola from a Cube

Truncated Tetrahedron as Convex Hull

Truncated Octahedron from a Cube

Villarceaux Circle

Six Edges of a Cube Meeting a Plane on a Conic

Icosahedron Plus Dodecahedron

Construction of a Rhombic Triacontahedron from a Dodecahedron

Construction of a Rhombic Dodecahedron from a Cube

Construction of a Rhombic Icosahedron from a Dodecahedron

Five Octahedra in an Icosidodecahedron

Hyperbolic Paraboloid