Draw af line in a specific angle around an object

Hi. I have a transform which I can draw a Ray from using e.g. Gizmos.DrawRay. My problem is that I don't know how to define an angle instead of a direction. E.g. I can understand that transform.forward - transform.right will send it 90 degrees to the left - but how do I say "draw a line in 12 degrees to the right of transform.forward"? With regards mpark