What is the principal feature of a convex mirror?

The principal feature of a convex mirror is that it curves outward. This outward curvature causes light rays that are parallel to the principal axis to diverge after reflecting off the mirror. Because of this divergence, convex mirrors are often used in situations where a wider field of view is needed, such as in vehicle side mirrors and security mirrors. The outward curve allows them to capture a larger area, which can help reduce blind spots and improve visibility.

The other options describe different types of mirrors or surfaces that do not apply to convex mirrors. For example, mirrors that curve inward are concave mirrors, which have fundamentally different properties. A flat surface pertains to plane mirrors, which reflect light without distortion but do not provide the same wide-angle view as a convex mirror. Multifaceted surfaces could refer to a variety of prisms or reflective structures but do not define the characteristics of a mirror type.