Forces in truss

I can't see that in your attached images? Is there an image missing?

 

Yeah, I see the two images in your OP and then again in post #4.

But I don't see this term:

 

Ok.
We still don't have the full problem statement as the dimensions of the structure don't appear in any of your three images.
I'm guessing the calc is some geometry to find some unknown length. Maybe E is a typo. Hard to say really, that's why PF homework rules state that you must include the entire question

 

I see no dimensions (or angles) on either image in post #6. The second image appears to be part of the worked solution, how could you be expected to solve the problem if the geometry of the truss isn't given?

 

Well, then the question is incomplete and unsolvable.

 

You don't need dimensions in a statically determinate frame - just the proportions. Guessing that the left hand triangle is in a 3/4/5/ proportion, the figures 6 and 8 make sense. The choices of forces as multiples of 14 suggest the question is looking for an answer that can be achieved without a calculator. The suggested reactions are wrong in my opinion and this reinforces the notion that it is useless to look for internal forces if the external reactions are incorrect. The external reactions should have been checked, for example by taking moments about any point not already used to obtain tham.