3.
\((1)\) 因为\(∠A=\)_____________\((\)已知\()\),所以\(AC/\!/ED(\) \()\).
\((2)\) 因为\(∠2=\)_____________\((\)已知\()\),所以\(AC/\!/ED(\) \()\).
\((3)\) 因为\(∠A+\)_____________\(=180^{\circ}(\)已知\()\),所以\(AB/\!/FD(\) \()\).
\((4)\) 因为\(∠2+\)_____________\(=180^{\circ}(\)已知\()\),所以\(AC/\!/ED(\) \()\).