How to Use Newton's Second Law to Solve for Tension in Statics Problems?

[VitaX]

Homework Statement

[PLAIN]http://img28.imageshack.us/img28/2106/241s.png

Homework Equations

ΣF = ma

The Attempt at a Solution

I'm really confused here, is using ΣF = ma even possible to find the tension here? Or do I have to utilize some other method, like law of sines?

 

[PhanthomJay]

The system is in equilibrium, so a = 0 . You might want to draw a free body diagram of member BC and sum moments about B, where the sum of moments (and forces) about B must equal _____??

 

[VitaX]

I think I figured it out for the most part, thanks for the hint.