Which vector diagram shows A as the sum of B and C?

[Precursor]

Homework Statement

Which of the following vector diagrams represent "A" as a sum of "B" and "C". (A=B+C)

http://img402.imageshack.us/img402/94/vectorsnj3.jpg​

Homework Equations

None that I know of.

The Attempt at a Solution

I think the answer is number 1, because A is the hypotenuse.

 

[arildno]

Consider:
How do you graphically add one vector to another?

 

[temaire]

Well actually, you can add vectors graphically because the resultant vector, which in this case is the hypotenuse, is equal to the sum of both legs of the triangle.

 

[arildno]

It is not the case of whether you CAN add vectors graphically together, but what that addition operation means, the relationship between the resultant vector and those two, and which of the pictures provides a correct description.

One does that, and hypotenuses (hypotenusi?, hypotena??) have nothing at all to do with it.