The local property of a curve represented by a number that characterizes how widely the tangent to the curve varies between two points on the curve.

The**mean curvature**between points *A* and *B* of an arc or a curve is the ratio between the change in the slope of the tangent from *A* to *B* and the length of the arc (or curve) *AB*.

### Example

In this illustration, where arcs *AB* et *BC* have the same length, the curvature between points *A* and *B* is greater than the curvature between points *B* and *C*, as the absolute value of the change in the slope of the tangent between points *A* and *B* is greater than the absolute value of the change in the slope of the tangent between points *B* and *C*.