Head to Tail Rule:

Given two unequal vectors:

1. Place the initial point of one vector at endpoint of the other vector.

2. Make a triangle from the joined vectors and the third vector is the vector sum of the two vectors.

If two vectors having the same direction but different magnitude, their vector sum is the sum of the magnitudes in the same direction.

If two vectors have the same magnitude and are in opposite directions their vector sum is a zero vector.

If two vectors are in opposite direction and have different magnitudes, then their vector sum is the difference in magnitudes of the vectors in the direction of the vector with the larger magnitude.