Given two vectors A and B with coords (x1,y1,z1) and (x2,y2,z2), the angle between these vectors from the origin is arcos((x1*x2 + y1*y2+ z1*z2)/||A||*||B||)
||A|| is the magnitude of A
Original formula is: Dot product of A and B = ||A||*||B||*cos(theta)
where theta is the angle between the vectors A and B
I'm sick of forgetting how to calculate the angle of a triangle inscribed inside a square prism. Not forgetting anymore.