如图,在棱柱\(ABCD\)\(-\)\(A\)\({\,\!}_{1}\)\(B\)\({\,\!}_{1}\)\(C\)\({\,\!}_{1}\)\(D\)\({\,\!}_{1}\)中,\(AA\)\({\,\!}_{1}⊥\)底面\(ABCD\),底面\(ABCD\)为直角梯形,其中\(AB\)\(/\!/\)\(CD\),\(AB\)\(⊥\)\(AD\),\(AB\)\(=\)\(AC\)\(=2\)\(CD\)\(=2\),\(A{{A}_{1}}=\sqrt{3}\),过\(AC\)的平面分别与\(A\)\({\,\!}_{1}\)\(B\)\({\,\!}_{1}\),\(B\)\({\,\!}_{1}\)\(C\)\({\,\!}_{1}\)交于\(E\)\({\,\!}_{1}\),\(F\)\({\,\!}_{1}\),且\(E\)\({\,\!}_{1}\)为\(A\)\({\,\!}_{1}\)\(B\)\({\,\!}_{1}\)的中点.
\((\)Ⅰ\()\)求证:平面\(ACF\)\({\,\!}_{1}\)\(E\)\({\,\!}_{1}/\!/\)平面\(A\)\({\,\!}_{1}\)\(C\)\({\,\!}_{1}\)\(D\);
\((\)Ⅱ\()\)求锥体\(B\)\(-\)\(ACF\)\({\,\!}_{1}\)\(E\)\({\,\!}_{1}\)的体积.