Say I have two sets of ordered points, $(x_1, y_1)$ and $(x_2, y_2)$, and $(x_3, y_3)$ and $(x_4, y_4)$. I want to map the first pair of coordinates to the second pair of coordinates (so the first coordinate maps onto the third, and the second to the fourth.)
I want to find the relative rotation the second pair of coordinates has with the first. I know the relative scaling ratio of the two coordinates (essentially the ratio of the distances between the two sets of coordinates). How can I go about finding the angle between the two?
