【附5套中考模拟试卷】湖北省咸宁?019-2020学年中考数学第三次调研试卷含解?- 百度文库 ر

ͼߡBOC=50㣬 BAC=25㣬 ACOB

OBA=BAC=25㣬 OA=OB

OAB=OBA=25. ѡA. 9A

ƽչͼУصмһΣݴ ⡿

һƽչͼ棬桰桰ԣ桰š桰ԣ䡱桰Ӧԣ ѡA 㾦

Ҫ弰չͼص⣬ȷչͼǽĹؼ 10A

ЩͼһЩƽͼΧɵģǵıʵļչƽͼΣƽͼγΪӦͼεչͼ.ͼαͼλÿж. ⡿

Ѹչͼۻ壬ͼλùϵֻ֪ѡAȷ. ѡA 㾦

⿼֪ʶ㣺չͼ.ؼ㣺չͼۻٹ۲. 11A

DAΪߡDΪڡABCڲһǵڡBǵһABĽ㼴Ϊĵ㣮 ⡿

ͼEΪĵ㣮ѡA

Ҫͼ-Ʊ任εжȷDһǵڡBCһǵ֪ǵʽĹؼ 12B

ɻͼõAB=AFAGƽ֡BADʿɵóıABEFΣεʿ֪AEBFʿɵóOB=4ɹɶɵóOA=3óAE=2AO=1 ѡB

㣺1ͼͼ2ƽıεʣ3ɶ4ƽߵ ⣺⹲6С⣬ÿС4֣24֣ 131 1

ݳεĶԱȣÿһǶֱǿɵAB=CDAD=BCBAD=C=90㣬Ȼá߽DZߡ֤RtABDRtCDBȫȣݵȵ׵ȸߵȽ ⡿

УRtABDRtCDB

ɣڳABCDУAB=CDAD=BCBAD=C=90㣬 RtABDRtCDBУ

?ABCD???BAD?C90? ?ADBC?RtABDRtCDBSAS

УBFDBFAABDAFDABEDFEAFDBCDȣȫȣ ʴΪ11 㾦

⿼ȫεжεʣԼȵ׵ȸߵεȣ 14

2 5 ⡿

⣺ɵãб 1 2 1 2 3 1 21 11 21 31 2 12 12 22 32 1 11 21 21 31 2 12 22 12 32 3 13 23 13 23 20еȿܵĽɫͬ8 ɫͬСĸΪ㾦

⿼б״ͼղȷбǽؼ 153

˳Ƚиָݵ㡢ǵǺֵȻٽм㼴. ⡿

82? 20512

2cos60

21=4-2

2=3 ʴΪ3. 㾦

⿼ʵ㣬漰˸ָݡǵǺֵص㷨ǽĹؼ. 16

3 2

֪׵2y1=k3y2=kɴ˿ɵ2y1=3y2μyֵ.

2⣺

߷y?y1kͼ󾭹A2y1B3y2 x2y1=k3y2=k 2y1=3y2

y13?.

y22ʴΪ

3. 2㾦ףA(ab)͵B(mn)ͬһy?Ĺؼ. 17

kͼϣab?mnǽx1 8

ͼɵôת̱ƽֳ24ȷݣоݡ֡3ݣȻøʹʽ⼴ô𰸣 ⡿

ͼת̱ƽֳ24ȷݣоݡ֡3ݣ ָھݡ֡ĸǣʴΪ

31? 2481 8㾦

⿼˸ʹʽӦãעʣ֮ȣ 18 (-1,-2)

Ϊy=x+122ߵĶʽ ݶʽص֪Ϊ12 ʴΪ12 㣺κʣ

⣺⹲9С⣬78֣Ӧд˵֤̻㲽裮 191342.