I'm trying to use vector dot product to get the angle between two vectors, but I'm puzzled by the results.
Given two vectors, A and B:
A(0.0, 0.2, 0.0)
B(0.8, 0.0, 0.0)
The angle between those, calculated with the dot product:
alpha= (acos(A*B)) * RAD_TO_DEG
properly returns 90°.
Now, let's have two vectors pointing in the same direction:
A(0.2, 0.2, 0.0)
B(0.8, 0.8, 0.0)
Would you guys explain me why in this case alpha is equal to 9.9°, while I'd expect to return 0°? Thanks