356 



APPENDIX 



CALCULATION OF THE 



THE HEXAGONAL PRISM. 



Its elements. 



The inclination of the adjacent lateral planes to 

 each other =: 120. 



Inclination of the terminal on the lateral planes 

 = 90. 



Plane angles of the summit = 120. 

 Lateral plane angles z= 90. 

 Ratio of the terminal to the lateral edge of 

 each particular prism can be deduced only by 

 means of some secondary plane. 

 Let us suppose it known, and expressed by 



m : n~ or by 1 : 

 m 



Its units of comparison. 

 For decrements on the angles of the terminal plane, 



the unit is ; and for decrements on the terminal 

 2 n 



edges it is ^ 8 "L60, as will be ghewn below . 



wR 

 For decrements on the lateral edges it is = 1. 



Fig. 356. 



The diagonals drawn on the terminal plane divide 

 that plane into six equilateral triangles. 



The law of any simple or mixed decrement on an 

 angle of the prism is deduced from the ratio of 



