在\(\Delta ABC\)中,设角\(A,B,C\)的对边分别为\(a,b,c\),向量\(\overset{\to }{{m}}\,=\left( \cos A,\sin A \right)\),\(\overset{\to }{{n}}\,=\left( \sqrt{2}-\sin A,\cos A \right)_{,若}\overset{\to }{{m\cdot }}\,\overset{\to }{{n}}\,=1_{,}\)
\((1)\)求角\(A\)的大小;
\((2)\)若\(b=4\sqrt{2},\)且\(c=\sqrt{2}a\),求\(\Delta ABC\)的面积.