How to get point a set distance along a direction

Hi all,
I have an angle. And I have a distance from an origin point.( in 3d but only on two axes - game will be top down)
What I want is to find another point that is the distance in the direction of the angle.
Im sure this is super easy but Im just not getting it right. I had been trying to work out the position values using Pythagoras’ theorem but no joy.

You could try this:

        float angle = 3.0f;
        Quaternion Rot = Quaternion.AngleAxis(angle,Vector3.forward);
        Vector3 Dir = Rot * Vector3.forward;
        Vector3 WorldDir = transform.TransformDirection(Dir);