What is the direction of angular velocity? Why is it in this direction? RT

What is the direction of angular velocity? Why is it in this direction? RT

Right hand rule
This setting is to unify the following mechanical calculation. According to the right-hand rule of cross product, the direction of angular velocity is defined. In fact, defining this direction and defining the positive direction of current are not very helpful for you to understand angular velocity, but just for the sake of unifying mathematics and physics and facilitating calculation
When it comes to theoretical mechanics, the direction of velocity determines the direction of acceleration