SYMMETRY OF SECONDARY PLANES. 



45 



Fig. 101, the same, with its obtuse terminal edges D replaced by 

 single planes. 



Fig. 102, the same, with its obtuse terminal edges F replaced by 

 single planes. 



Fig. 101. Fig. 102. 



Fig. 103, the same, with the oblique edges of the prism replaced 

 by single planes. 



Fig. 104, the same, with the lateral edges of the prism replaced 

 by single planes. 



Fig. 103. Fig. 104. 



Fig. 105, the same, with obtuse solid angles O replaced by single 

 planes. 



Fig. 106, the same, with acute solid angles A replaced by single 

 planes. 



Fig. 105. Fig. 106. 



