Why are rear-view and side view mirrors on vehicles convex?

Rear-view and side mirrors on vehicles are convex (curved outwards) to provide a wider field of view than a flat mirror would. This is crucial for safety. While objects appear smaller than they actually are, the significantly broader view allows drivers to see more of their surroundings, including blind spots that a flat mirror would miss. The trade-off of smaller-appearing objects is worth it for the increased awareness of the vehicle's surroundings.