Hi there i have the attached problem, the struture is indeterminate so i need to solve in terms of R, I have chosen the secion BD as R.

Resolving the joints i get:

Joint B

H = 0

F1 cos t1 + 30 + F2 cos t2 + R = 0

F1 = F2

So

-2Fcos t = 30 + r

- F = (15 + R ) / Cos t

V = 0

30 + 2fcos t + R = 0

R = (30 - 2f cos t)

Joint D

2 F cos r + R = 0

-2F = R / cos t

F = - (1/2) * (R / cos t)

any help on these would be great cause when i reinsert to end equations i devlop i dont get the right kind of figures, Trig is not my strong point lol.

Many thanks