Final answer:
The direction of a vector is indicated by the head of the arrow. The length of the arrow represents the vector’s magnitude, and the arrowhead points in the same direction as the vector.
Step-by-step explanation:
When illustrating vectors, the indicator of the direction of the vector is the head of the arrow. Vectors are represented graphically by arrows, where each arrow has a tail at the starting point and a head at the end point, indicated by an arrowhead. The length of the arrow correlates to the vector's magnitude, which is a positive scalar value. Understanding the direction of vectors is essential, as it can be denoted in various ways, such as by using a plus (+) or minus (-) sign in one-dimensional motion or by an angle measurement in two-dimensional space. The direction can also be referenced to a compass direction, another vector, or a fixed point.