bullet reflected

think about bullets "reflected". meaning: imagine a bullet fired (with raycast) in 2d game and hit a metal wall - it will bounce adhering to "the angle of incidence equals the angle of reflection" rule

how to calculate it, knowing it's a 2d game, and it will use RaycastHit. am I looking at a solution somewhere here: http://unity3d.com/support/documentation/ScriptReference/RaycastHit.html ?

edit:

function Update () {
var hit : RaycastHit;
if (Physics.Raycast (Camera.main.ScreenPointToRay(Input.mousePosition), hit))
Debug.DrawRay(hit.point, hit.normal * 10, Color.red);
var incidenceAngle = hit.point - Camera.main.transform.position;
Debug.DrawRay(hit.point, -incidenceAngle* 10, Color.yellow);
var reflectionAngle = hit.normal + incidenceAngle;
Debug.DrawRay(hit.point, reflectionAngle * 10,Color.green);
}

Here I'm drawing normal, incidence angle and reflection angle, but I'm not really doing great with reflection angle, do I..

edit2: in http://www.cs.jcu.edu.au/Subjects/cp2060/2001/lectures/illumination/node9.html r = 2n (n.l)-l;

what's that "(N.L)" and why it's inserted after "2n" without any "+" or "*" or anything that could suggest what to do with it?