2012徐州数学中考试题(6)

（2）解法一： △ABF≌△DCE，

······················································································································ 4分 B C． ·

四边形ABCD是平行四边形， AB∥CD．

B C 180 ．

············································································································· 5分 B C 90 ． ·

···································································································· 6分 四边形ABCD是矩形． ·

解法二：连接AC，DB． △ABF≌△DCE， AFB DEC．

··········································································································· 4分 AFC DEB． ·

在△AFC和△DEB中，

AF DE， AFC DEB，CF BE， △AFC≌△DEB．

······················································································································· 5分 AC DB． ·

四边形ABCD是平行四边形，

···································································································· 6分 四边形ABCD是矩形． ·

22 （1）200人---------------------------------------------------------2分 （2）乐器组60人（图略），书法部分圆心角 36°---------------------------4分 （3） 绘画组需教师23人 书法组需教师5人 舞蹈组需教师8人

乐器组需教师15人------------------------------------------------------6分

23 证明:连结AG.

∵A为圆心,∴AB=AG.

∴∠ABG=∠AGB.-------------------------------------------------------2分 ∵四边形ABCD为平行四边形.

∴AD∥BC.∠AGB=∠DAG,∠EAD=∠ABG.------------------------------------4分 ∴∠DAG=∠EAD.

FG .--------------------------------------------------------8分 ∴EF