OA

.Po..A.B12:PAPBPOAPB

OPAPBABOAOBOPPA = PB OPA=OPBPAPBOAB OAPAOBPB OAP=OBP=90 OA=OBOP=OP RtAOPRtBOP(HL) PA = PB OPA=OPB

APOBPAPBO,AB,POOCCACB?.CA=CBPAPBO,AB PA = PB OPA=OPB PC=PC PCA PCB AC=BCC

BOPAHDC

PAPBOABOPODEABC

BAPOCED1OAPAOB PBAB OP3AOP BOP AOC BOC ACP BCP4ABP AOB2OACOAC=OBC=APC=BPC

PBAO231

ABC

, ABCOBC CA AB D E F AB9BC 14,CA 13, AF,BD,ECO, ABCOBC CA AB D , E F FDEA, ABCOBC CA AB D , E F B0CA

1ABCD ABBCCDDAOLMNP12

ABCDEFAC,ABCBDBFACEAD=AE BD=BF CE=CFABC=2BD

2.PAPBOABE PAPBCDPA=7cm(1)PCD(2) P=46,CODE

ABOADDCBCAEBBC=9AD=4OE.

1ABC r , ABC l ,ABC OOAOBOCrrr

..5,12,13.