A portion of a curve.

**Arc of a graph**

Line or edge that joins two consecutive vertices (distinct or not) of a directed graph.**Arc of a circle**

The portion of a circle between two given points on the circle.**Arc of a curve**

The portion of a curve between two points on the curve.

### Notation

The notation used to refer to an arc with endpoints *A* and *B* is: \(\stackrel{\frown}{\textrm{AB}}\).