Question

What is Radii of curvature?
Answer fast.

Answer 1

Answer:

the radius of a circle which touches a curve at a given point and has the same tangent and curvature at that point

Answer 2

$\huge \bf{Radii \: of \: Curvature.}$

The radii of the two imaginary spheres of which the lens is a part are called radii of curvature of the lens. A lens has two radii of curvature. These may or may not be equal.