所求角平分线;
如图②,连接AO并延长,与⊙O交于点D,连接PD,即为所求角平分线.
(2)∵AD是直径,∴
ABD
=
ACD
,
又∵AB=AC,
∴
AB
=
AC
.
∴
BD
=
CD
,
所以PD平分∠BPC.
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