\begin{theindex}

  \item  barycentric coordinates, 185
  \item  plane, radical of two spheres, 38

  \indexspace

  \item angle, complementary, 56
  \item angle, polar, 56
  \item angle, polyhedral regular, 128
  \item axis of symmetry, 96

  \indexspace

  \item Bretshneider's theorem, 67
  \item Brianchon's theorem, 177

  \indexspace

  \item center of a regular polyhedron, 129
  \item center of a spherical face, 135
  \item center of homothety, 97
  \item center of inversion, 206
  \item center of mass, 184
  \item Ceva's theorem, 53
  \item Ceva's theorem, first, 53
  \item Ceva's theorem, second, 54
  \item circumscribed sphere, 129
  \item coefficient of homothety, 97
  \item coordinates, barycentric, 185
  \item Crelle's formula, 207
  \item cube, 128

  \indexspace

  \item degree of a point relative to a sphere, 38
  \item degree of inversion, 206
  \item dodecahedron, 128
  \item dual polyhedron, 130

  \indexspace

  \item equifaced tetrahedron, 68
  \item Euler's formula, 114, 216

  \indexspace

  \item formula Euler, 216
  \item formula, Crelle, 207
  \item formula, Euler, 114
  \item formula, Krell, 67

  \indexspace

  \item homothety, 97
  \item homothety, the center of, 97
  \item homothety, the coefficient of, 97

  \indexspace

  \item icosahedron, 128
  \item inertia, moment of, 185
  \item inscribed sphere, 129
  \item inside tangency, 166
  \item integer lattice, 193
  \item inversion, 206
  \item inversion, center of, 206
  \item inversion, degree of, 206

  \indexspace

  \item Jacobi identity, 94

  \indexspace

  \item Krell's formula, 67

  \indexspace

  \item lattice, integer, 193
  \item law of cosines for a trihedral angle, first, 51
  \item law of cosines for a trihedral angle, second, 51
  \item law of sines for a tetrahedron, 66
  \item law of sines for a trihedral angle, 51

  \indexspace

  \item median of tetrahedron, 184
  \item Menelaus's theorem, 53
  \item Menelaus's theorem, first, 53
  \item Menelaus's theorem, second, 54
  \item mixed product, 95
  \item moment of inertia, 185
  \item Monge's point, 96
  \item motion, 97
  \item motion, orientation changing, 98
  \item motion, orientation preserving, 98

  \indexspace

  \item node (of a lattice), 193

  \indexspace

  \item octahedron, 128
  \item order of an axis of rotation, 138
  \item orthocentric tetrahedron, 69
  \item outside tangency, 166

  \indexspace

  \item perpendiculars, theorem on three, 11
  \item point, Monge, 96
  \item polyhedron regular, 128
  \item polyhedron, dual, 130
  \item product, mixed, 95
  \item product, vector, 94
  \item projection, stereographic , 207

  \indexspace

  \item radical plane of two spheres, 38
  \item ratio of oriented segments, 53
  \item regular polyhedral angle, 128
  \item regular polyhedron, 128
  \item rotation, 97

  \indexspace

  \item self-superimposition, 130
  \item solid angle, value of, 39
  \item sphere of 12 points, 69, 70
  \item sphere of 24 points, 70
  \item sphere, circumscribed , 129
  \item sphere, inscribed, 129
  \item spheres tangent from the inside, 166
  \item spheres tangent from the outside, 166
  \item stereographic projection, 207
  \item symmetry through line, 96
  \item symmetry through point, 96
  \item symmetry with center, 96
  \item symmetry with center, central, 96
  \item symmetry, axial, 96
  \item symmetry, axis of, 96

  \indexspace

  \item Teatet, 128
  \item tetrahedron, 128
  \item tetrahedron orthocentric, 69
  \item tetrahedron, equifaced, 68
  \item theorem on three perpendiculars, 11
  \item theorem, Bretshneider, 67
  \item theorem, Brianchon, 177
  \item theorem, Ceva, 53
  \item theorem, Ceva's, first, 53
  \item theorem, Ceva's, second, 54
  \item theorem, Menelaus, 53
  \item theorem, Menelaus's, first, 53
  \item theorem, Menelaus's, second, 54

  \indexspace

  \item value of the solid angle, 39
  \item vector product, 94

\end{theindex}