APPENDIX CALCULATION OF THE 



RHOMBOID. 



Its units of comparison. 



Fig. 358. 



d 



The following are the units of comparison in rela- 

 tion to the decrements producing the several classes 

 of modifications contained in the tables. 



Class b. c, e, g, A*, unit cos ' J -, being the ratio 



K, 



of | an oblique diagonal 

 : an edge. 



Class h* the unit is stn> T ^ ', when the rhomboid 

 sin. A 5 



is acute. 



sin. \ A l 



and 



, 



when it is obtuse. 



