\[\angle BOD = 168{^\circ};\]
\[\angle AOB = 180{^\circ} - развернутый.\]
\[1)\angle AOD = \angle AOB - \angle BOD =\]
\[= 180{^\circ} - 168{^\circ} = 12{^\circ}.\]
\[2)\ так\ как\ OD -\]
\[биссектриса\ \angle AOC,\ то\ \]
\[\angle AOD = \angle DOC = 12{^\circ}.\]
\[3)\ \angle AOC = \angle AOD + \angle DOC =\]
\[= 12 + 12 = 24{^\circ}.\]
\[Ответ:\ \angle AOC = 24{^\circ}.\]