Answer:
Explained below
Step-by-step explanation:
For the geometric meaning, I've attached a parallelogram showing two vectors a and B and also the angle between them as θ.
We can see that the two vectors are adjacent to each other.
So the magnitude of the product of the two vectors is simply the area of the parallelogram which is base x height. Thus;
Magnitude = |a| sin θ × |b|
This can be rewritten as;
|a|•|b| sin θ