In the figure below, A,B,C,D,E,and Fare the vertices of a regular hexagon centered at the origin. Express each of the following vectors in terms of aOÁ and b = OB:

\overrightarrow{A B} \vec{E} \overrightarrow{A D} \bar{C} . \overrightarrow{A C} \overrightarrow{B C}+\vec{D}+\overrightarrow{F A}