SYMMETRY OF SECONDARY PLANES'. 



41 



Fig. 84, the same, with the greater terminal edges replaced by 

 single planes. 



In the right rhombic Prism, the terminal edges are similar; but 

 the two opposite, obtuse lateral edges, and the solid angles which 

 terminate them, are different from tfie acute lateral edges, and the 

 corresponding solid angles. The modifications of this form are there- 

 fore in conformity with these relations. 



Fig. 85 represents the right rhombic Prism, with its obtuse later- 

 al edges replaced by tangent planes. 



Fig. 84. 





T 



Fig. 86, the same, w r ith its obtuse lateral edges replaced by two 

 planes. 



Fig. 87, the same, with its acute lateral edges replaced by two 

 planes. 



Fig. 8G. 



Fig. 87. 



Fig. 88, the same, with its obtuse solid angles replaced by single 

 planes, which intersect the terminal plane parallel to its greater 

 diagonal. 



Fig. 89, the same, with its acute solid angles replaced by single 

 planes, which intersect the terminal plane parallel to iU shorter 

 diagonal. 



4* 



