In a horizontal plane, take the x-axis along the line joining a sound source S at (0, 0) and a listener L at (6.0, 0), with all distances in metres. A flat reflecting panel is to be erected at the point P(2.0, 3.0). Find the angle (to the nearest degree) that the face of the panel must make with the x-axis so that sound from S reaches L after a single reflection at P.