Well, inspecting above sketch leaves you with no choice. You got to do the overall equilibrium equations first and then hope for the best.
From time to time there is also more than one path to happiness.

Equlibrium of .. gives value of forces ...
Entire truss R1 , R2y , R2x
Joint A FAB , FAE
Joint B FBC , FBE
Joint E FCE , FEF
Joint F FCF , FDF
Joint C FCD

In principle I am done now. But I have not used one equlibrium equation on point C and none at point D ( = three unused equations because of the three global equilibrium equations I used to start with ).
So, I would use these three unused equations to see whether they are satisfied for the values of the forces I previously had obtained. If NOT >>>> I better find my error.

In important note : Only in the rarest of circumstances will you find that your check-up equations are exactly satisfied. There always will remain some error due to round-off. So, your problem will be to judge whether your errors can be explained away by round-off or are due because you made an honest error somewhere.
My personal strategy of judgement is the following : If I calculate all forces (and angles etc.) to 3 digits accuracy I can at best expect to have my check-up equations satisfied to about 0.1 % (0.01% for 4 digits and so on). My relative error for each equation is calculated the following way : if I get for example 0.5 Newtons (instead of 0 ) and my largest force is 200 newtons my relative error is 0.5/200*100% = 0.25% . It is highly probable that this error is due to round-off. If I would have gotten 2.5 % I would feel very uneasy and check my results.


Last revised: Aug.5 , 1997
Zig Herzog