Geometry Animations

Triangles and Circles

• Dudeney's Dissection
• Morley's Theorem
• Feuerbach's Nine Point Circle
• Steiner's Porism
• Multiple Reflections
  in the Sides of a Rotating Triangle

Curves

• Conic Sections
• Osculating Circles of an Ellipse
• Evolutes of Limacons
• Involutes of a Lemniscate
• Trihedron Moving on a Trefoil Knot

Polyhedra

• Wythoff's Three-Dimensional
  Kaleidoscope

Vertex Truncation

• tetrahedron
• cube
• dodecahedron

Edge Truncation

• tetrahedron
• octahedron
• icosahedron

Still Pictures

• multiple transformations of
  polygons
  platonic solids
  
  
• combining 3D rotations
  
  
• more 3D transformations
  
  
• inscribed platonic solids
• double duals