Angle \(\angle AOK\) is a central angle because its vertex is located at the center \(O\) and whose sides \(\overline{OA}\) and \(\overline{OK}\) are the radii of the circle which terminate at the points on the circle \(A\) and \(K\).

The central angle \(\angle AOK\) intercepts the minor arc \( \overset{\Large\frown}{AK}\). Remember that the measure of a central angle is equal to the measure of its related arc.

Because \(m\angle AOK = 85^\circ\) it implies that \( m\overset{\Large\frown}{AK}=85^\circ\)