Hi, I am trying to write a C++ program that gets angles between vector.

I know how to get a direction of a vector..due to the degree of rotation.

But what I don't fully understand is the angle between 2 vectors.

For example if I have two vectors at point1(6,4) and point2(10,3)

to make point1 rotate in order to face point2 I have to subtract

new point(10-6, 3-4) atan(4/-1)..but thing is I don't understand how that is the angle between the 2 vectors..

When I subtract 2 vectors it gives me a new vector. which tells me how much I need to move to get to the endpoint. so from the above explanation..to move from point to point2 I need a velocity of newpoint(4,-1)

to get the angle between them..doesn't make much sense to me

atan2(4/-1)..does that give me the angle between the new vector and the origin (0,0) or the origin of one of the points? Can someone please clarify...thanks

If it was only one vector I understand it perfectly.but I just can't visualize the angle between 2 vectors.