1、一、 AE=BE= CDAB= CD过圆心(即CD是直径)证明:= ,= = = 圆周 CD过圆心(即CD是直径) 连接OA,OB = AOD=BOD 在AOE和BOE中 OA=OB AOE=BOE OE=OE AOEBOE(SAS) AE=BE,AEO=BEO=90 CDAB二、 = = CDABAE=BE CD过圆心(即CD是直径)证明:连接OA,OB 在AOE和BOE中 OA=OB AE=BE OE=OE AOEBOE(SSS) AOE=BOE,AEO=BEO=90 AOE=BOE = = ,= = = 圆周 CD过圆心(即CD是直径) AEO=BEO=90 CDAB 三、 = = CD
2、AB AE=BE CD过圆心(即CD是直径) 证明过程同上四、 = = AE=BECDAB CD过圆心(即CD是直径)证明:连接OA,OB CDAB AEO=BEO=90 在RtAOE和RtBOE中 OA=OB OE=OE RtAOERtBOE(HL) AOE=BOE,AE=BE AOE=BOE = = ,= = = 圆周 CD过圆心(即CD是直径)五、 = = AE=BE CDAB CD过圆心(即CD是直径)证明过程同上六、 = = AE=BECD过圆心(即CD是直径) CDAB 证明:连接OA,OB CD过圆心(即CD是直径) = = 圆周 = = AOE=BOE 在AOE和BOE中 OA
3、=OB AOE=BOE OE=OE AOEBOE(SAS) AE=BE,AEO=BEO=90 CDAB七、 = = AE=BECD过圆心(即CD是直径) CDAB 证明过程同上八、 = AE=BE = CDAB CD过圆心(即CD是直径)证明:连接OA,OB OA=OB OAB为等腰三角形 AE=BE,CDAB OD平分AOB且CD过圆心 AOD=BOD = CD过圆心(即CD是直径) = = 圆周 = = 九、 = AE=BE = CD过圆心(即CD是直径) CDAB 证明:连接OA,OB 在AOE和BOE中 OA=OB AE=BE OE=OE AOEBOE(SAS) AOE=BOE,AEO=BEO=90 CD过圆心 AOD=BOD,CDAB = CD过圆心(即CD是直径) = = 圆周 = = 十、 = CDAB = CD过圆心(即CD是直径) AE=BE 证明:连接OA,OB CDAB AEO=BEO=90 在RtAOE和RtBOE中 OA=OB OE=OE RtAOERtBOE(HL) AOE=BOE,AE=BE AOE=BOE,CD过圆心 AOD=BOD = CD过圆心(即CD是直径) = = 圆周 = =