题目

(本题8分) 如图，EF∥AD，∠1=∠2, ∠BAC=70°，将求∠AGD的过程填空完整。解：∵EF∥AD∴∠2=        （                    ）又∵∠1=∠2∴∠1=∠3（                    ）∴AB∥      （                    ）∵∠BAC+         =180°（                    ）∵∠BAC=70° ∴∠AGD=           。令a=log213，b=213，c=212，则a，b，c的大小关系为a＜b＜ca＜b＜c．