2021-2022上八年级数学段考参考答案(提示)1--5DCBCD5--10BBCBC11.八12.12013.3614.8415.1216.317.(1)略....3分(2)4.5....5分18.80°19.证明过程(略)证明过程完整......8分20.(1)尺规作图规范完整......3分(2)证明过程(略)完整.....9分21.(1)BD⊥AC.......2分BD平分AC......4分或(∠BAD=∠BCD)(2)证明:(略)......8分(3)24....11分22.112.523.(1)==......2分(2)135°......4分(3)∠AME=∠AMD......12分提示:先证明ΔAEC≌ΔABD.得到BD=EC、∠AEC=∠ABD.作AH⊥EC于H,AP⊥BD于P,
证明ΔAEH≌ΔABP.得到AH=APAM平分∠EMD∠AME=∠AMD