There is an Angle between two Vectors component in the Vector>Vector tab. This will give the angle in Radians between lines. However, if you need to find which direction the angle is for rotation purposes then you will need to use the Cross Product component (Same location) to get the Z direction. In the example below the direction from A to B is negative. So you can multiply the number by the unitized Z component of the Cross Product.
Angle can be measured only between vectors. Lines (and linear curves) can be treated as vectors since they have the same tangent along their domain. Curved splines do not have this property and therefore there is no one answer to what angle is between them.
I suppose you want to find the angle between two curves at their intersection point?
Thank you all! I wanted to know the angle between two curves at their intersection point, and I was searching Grasshopper under curve components ignoring that it is an action compeletly related to the vectors. Now I know why it is among the vector components, David:)
Regards
Maryam