Definition: 3.07: Angle of a Segment
And the angle of a segment is that contained by a straight line and a circumference of a circle.
An arc is one of the two parts into which a secant divides the circumference. The larger is called the major conjugate arc, and the smaller is called the minor conjugate arc.
Definitions: 1 2 3
Adapted from (subject to copyright, with kind permission)
- Fitzpatrick, Richard: Euclid's "Elements of Geometry"