36 



TERMINOLOGY. 



Fig. 57, the same, with its edges replaced by tangent planes. 

 Fig. 58, the same, with its edges replaced by two planes. 



Fig. 57. 



Fig. 58. 



Fig. 59, the same, with its solid angles replaced by three planes j 

 resting on the primary planes. 



Fig. 60, the same, with its solid angles replaced by six planes. 



Fig. 61, represents the regular Octahedron, with its solid angles 

 replaced by tangent planes. 



Fig. 59. 



Fig. 60. 



Fig. 61. 



Fig. 62, the same, with its edges replaced by tangent planes. 

 Fig. 63, the same, with its edges replaced by two planes. 



Fig. 62. 



Fig. 63. 



Fig. 64. 



Fig. 64, the same, with its solid angles replaced by four planes, 

 resting on the primary planes. 



