3. As shown in the figure, the side length of $\triangle A B C$ is $2, F$ is the midpoint of $A B$, extend $B C$ to $D$, such that $C D=B C$, connect $E D$ intersecting $A C$ at point $E$. Then the area of quadrilateral $B C E F$ is
3. $\frac{2}{3} \sqrt{3}$