398 



and 



PRACTICAL MATHEMATICS 



= - {1-515 + 2-499 cos 30 + 2-810 cos 60 



- 2-496 cos 60 - 0-566 cos 30} 

 = - (1-515 + 1-933 cos 30 + 0-314 cos 60} 



0-558 



3-064. 



2-Z.96 



2-810 



O-566, 



Z-A99 



1-515 



FIG. 134. 



To get A 2 and B 2 (Fig. 135). 

 Then A 2 = - (0-720 sin 60 - 1-349 sin 60} 



0-629 sin 60 C 



2-069 



I-5A9 



FIG. 135. 



