What is the role of A+B+C in finding vector components?

[White_Noise]

Homework Statement

http://img32.imageshack.us/img32/5364/325n.png

The Attempt at a Solution

I don't know how to approach this simple problem. I don't know what role A+B+C = -1.90i plays. Even if the vector of B is found, I don't understand how to find the components of B.

 

[rock.freak667]

Clearly you can see that the resultant of A+B+C gives something i right? That means the sum of the j components=0.

Can you split B into i and j components and use what I said before?

 

[White_Noise]

I got it, thanks. I was confused because I didn't know that i and j corresponded to x and y.