I have a plane, defined by three points. For example:
O = Vector3.zero
A = Vector3(3,15,5)
B = Vector3(2,4,10)
I need to find fourth point var D : Vector3, knowing that point lies in the same plane, distance from A is 10 units and angle between my new point D and A from B (angle DBA) is 40 Euler degrees (in the direction of O).