Let we consider two vectors A and B inclined at an angle θ. Let they may be represented in magnitude and direction by two sides OP and PQ of ∆OPQ, taken in same order. Then, according to Triangle Law of vector addition, the resultant R is given by the closing side OQ, taken in opposite order.
If the resultant vector R makes an angle β with the direction of vector A, then from ∆QNO,
Subtraction Of Vectors (Analytical Method)
If there are two vectors A and B at angle θ. If we have to subtract B from A, then first invert the vector B and add with vector A.