Let $ABCDEF$ be a such convex hexagon that $$ AB=CD=EF\; \text{and} \; BC=DE=.FA$$Prove that if $\sphericalangle FAB + \sphericalangle ABC=\sphericalangle FAB + \sphericalangle EFA = 240^{\circ}$, then $\sphericalangle FAB+\sphericalangle CDE=240^{\circ}$.