How to calculate the angle of a vector from the vertical?

Question

Im trying to find out the angle (in degrees) between two 2D vectors. I know I need to use trig but I\'m not too good with it. This is what I\'m trying to work out (the Y axi

Answer 1

My first guess would be to calculate the angle of each vector with the axes using atan(y/x) and then subtract those angels and take the absolute value, that is:

abs(atan(y/x) - atan(y1/x1))