Find a position of a point in 3d space moving around a vector with uniform circular motion

Question

Let's say I have a point A in a 3d space, and I want to move it with a uniform circular motion around the unit vector n.

So I know the position vector of A, O and the unit vector n (normal to the plane where O, A and B resides), and I know the angle AOB.

What is the quickest way to find the position of B ?

Answer 1

How about just applying the rotation matrix about an axis and angle?

Answer 2

In mathspeak, that would be OB = OA * cos(theta) + (OAxn) * sin(theta)