Coplanar circles with the same ceneter
concentric circles
two arcs that are in the same or congruent circles and have the same measure
congruent arcs
two circles that have congruent radii
congruent circles
the set of all points outside circle
exterior of a circle
A segment of a secant that lies in the exterior of the circle with one endpoint on the circle
external secant segment
an angle whose vertex is on a circle and whose sides contain chords of the circle
inscribed angle