1. The problem statement, all variables and given/known data In this question , the author doesnt stated which direction ( either horozintal support of the pinned E or the vertical support force at pinned E to be selected as redundant ) . So , I tried this problem by applying the vertical force support at E as redundant . 2. Relevant equations 3. The attempt at a solution I have done the step 1 , which is to find all the member force in the truss . ( The working is not shown here) . However , I am having problem in part 2 , which is to find the member force by applying 1 unit load (virtual foce) ... By doing so , all the external force is removed and the new member forces are to be found . I used ALTERNATIVE method to find the forces in the member . However , i cant balance the forces at joint C . What's wrong with my working ?