Thread: Need help constructing a vector

Hello There

I have two existing vectors. I wish to construct a third vector which is in the same plane as the existing 2 vectors, and makes a specific angle with one of them. What method could I use to do this?

If we call your two vectors u and v then the vector you want will be u + a v with a chosen to achieve the required angle. You can use the scalar product u . ( u + a v ) to help you.