Radius of Curvature (applications) - Curvature

Curvature

A simple, if crude, definition of a circle is "a curved line bent in equal proportions, where its endpoints meet". Curvature, then, is the state and degree of deviation from a straight line—i.e., an "arced line". There are different interpretations of curvature, depending on such things as the planular angle the given arc is dividing and the direction being faced at the surface's point. What is concerned with here is normal curvature, where "normal" refers to orthogonality, or perpendicularity. There are two principal curvatures identified, a maximum, κ₁, and a minimum, κ₂.