Solve 4 Unknowns: Statics Question

[Ry122]

[PLAIN]http://img38.imageshack.us/img38/6997/forces99.jpg

I'm unsure how to go about solving this. There's 4 unknowns. Ax Ay Cx and Cy but isn't there only 2 equations (sum of forces in x and y direction are equal to 0) that can be created in this situation?

 

[vela]

The net moment on each strut should be 0 as well.

 

[radou]

No, there are two unknowns, the forces A and C at the supports. There are two equations. Every one of your "unknowns" must be written in terms of A and C (i.e. their projections onto the x and y-axis).

 

[simianmirror]

I am also stuck on this question. any hints would be much appreciated :)

 

[pongo38]

Draw the triangle of forces for joint B

 

[pongo38]

You have two additional equations. One relates Ax and Ay. The other relates Cx and Cy. Can you sketch in the expected directions of the reactions?