Question

what is the relation between focal length and radius of curvature ​

Answer 1

Answer:

The focal length (f) of a lens is the distance between the center of the lens and the point at which the reflected light, of a beam of light travelling parallel to the center line, meets the center line (principal axis). The radius of curvature (r) is the radius of the lens that forms a complete sphere.

Answer 2

Answer: Focal length is half the radius of the curvature.

Explanation: I am guving an attachment. It is done for concave mirror. Similarly it can be done for convex mirror.