The sun’s rays hit the earth’s surface at an angle of 50 degrees. At what angle to the horizon

The sun’s rays hit the earth’s surface at an angle of 50 degrees. At what angle to the horizon should a flat mirror be placed so that the rays, reflected from it, go horizontally?

The beam incident on the mirror is divided into two equal parts by the normal to the surface of the mirror at the point of incidence. The normal in this case makes an angle of 25 degrees with the horizon. The mirror is rotated 90 degrees relative to the normal. In total, we find that the mirror surface (or mirror) forms an angle of 115 degrees with the horizon.
Answer: 115 degrees (between the horizon and the back of the mirror – 75 degrees)