CHAP. XH.] METHODS COMBINED. 199 



For the lower flanges, in like manner : 



B b x 10 = + 61.55 - 0.97 x 10 or B b = + 5.18 

 Bd x 10 = + 61.55 0.97 x 30 or Bd = + 3.24 

 B/ x 10 = + 61.55 - 0.97 X 50 or B/= + 1.3 

 BA x 10 = + 61.55 - 0.97 x 70 or B h = 0.6 



For the diagonals, since the angle ma.de by these with the 

 vertical is 45 = and hence sec. d = 1.414, we have : 



a I = 0.97 x 1.414 = + 1.37 I c = - 1.37, etc. 



We can thus fill out the column for 1^. 



In similar manner also we fill out the column for 1^, Lg, etc. 



So also for each of the apex loads in the span itself. Thus 

 for P 1? we have moment at D = + 158.92 and shear at D = 

 + 36.17. We have then (Fig. 88). 



A a X 10 = 158.92, or A a = 15.89 tons. 

 A G x 10 = - 158.92 + 36.17 x 20 - 40 x 10, or 



A<?= + 16.4 



A e x 10 = - 158.92 + 36.17 x 40 - 40 x 30, or 

 A e = + 8.8, etc. 



So also for under flanges : 



B5 x 10 = -t- 158.92 - 36.17 X 10, or B b = - 20.2. 

 Bd x 10 == + 158.92 - 36.17 x 30 + 40 x 20, or 

 Bd= 12.6. etc. 



Also for the diagonals we have : 



a b = 36.17 x 1.414 = + 51.1, b c = (40 - 36.17) 1.414 = + 5.2, 

 cd= 5.2, etc. 



We can thus fill out the column for P 1} and in similar man- 

 ner the columns foi P 2 , P 3 , etc. 



