As shown in the figure, AB is 6, that is, 6 meters to the east and BC is 8, that is, 8 meters to the north. The length of AB here is 6, and the direction to the east is 6. You can see that AB has both direction and length. This quantity is called a vector, that is, it has both direction and length. The topic requires the addition of two vectors. The addition is based on the triangle rule, that is, a triangle is constructed with AB and AC as adjacent sides, then the other side AC is the sum of vectors, and the direction points from the starting point of one vector to the end point of the other vector, understand? The resultant displacement of this problem is (6 2+8 2) =10 under the radical sign. Remember that displacement is a vector with magnitude and direction.