5. 在等腰梯形ABCDABCDABCD中,已知AB//DCAB//DCAB//DC,AB=2AB=2AB=2,BC=1BC=1BC=1,∠ABC=60∘\angle ABC=60\circ∠ABC=60∘,点EEE和FFF分别在线段BCBCBC和DCDCDC上,且BE→=23BC→\overrightarrow{BE}=\frac{2}{3}\overrightarrow{BC}BE=32BC,DF→=16DC→\overrightarrow{DF}=\frac{1}{6}\overrightarrow{DC}DF=61DC,则AE→⋅AF→\overrightarrow{AE}\centerdot \overrightarrow{AF}AE⋅AF的值为 2918\frac{29}{18}1829 .