Concave mirrors are used in torches, search-lights, and vehicle headlights to produce powerful parallel beams of light.

The laws of reflection are followed, ensuring that at the point of incidence, the angle of reflection equals the angle of incidence.

The incident ray is reflected obliquely, following the laws of reflection at the point of incidence, making equal angles with the principal axis.

The incident rays fall on the mirror along the normal to the reflecting surface, ensuring that the laws of reflection are followed, and the light is reflected back along the same path.

The ray of light will emerge parallel to the principal axis on the opposite side of the convex lens.