解:AD=AB,则∠ABE=∠AEB;故∠A+∠ABE+∠AEB=180度=∠A+2∠ADB;同理:∠C+2∠CEB=180度.所以:(∠A+∠C)+2(∠ADB+∠CEB)=360度;即:90度+2(∠ADB+∠CEB)=360度,∠ADB+∠CEB=135度.则:∠DBE=180度-(∠ADB+∠CEB)=45度.
45度