如图，已知 $\mathit{AB}//\mathit{CD},\angle \mathit{BAF}=\frac{1}{4}\angle \mathit{BAE},\angle \mathit{DCF}=\frac{1}{2}\angle \mathit{DCE}$， $\angle \mathit{EAF}=\angle \mathit{DCF}$，且 $\angle \mathit{AEC}+\angle \mathit{AFC}=140°$，则 $\angle \mathit{AEC}$的度数是多少?