Which of the following mirrors are used as rear-view mirrors in vehicles?

Convex mirror

Convex mirrors are commonly used as rear-view (wing) mirrors in vehicles.

These mirrors are fitted on the sides of the vehicle, enabling the driver to see traffic behind him/her to facilitate safe driving.

Convex mirrors are preferred because they always give an erect, though diminished, image. Also, they have a wider field of view as they are curved outwards.

Thus, convex mirrors enable the driver to view much larger area than would be possible with a plane mirror.