点P是角C平分线与AB的交点
AC=6√5,[AC^2=AB^2+BC^2=144+36=180=9*4*5]
设PB=X,作PD⊥AC于D,PD=PB=X
AP=12-X
AD^2=AP^2-PD^2
AD=√[(12-X)^2-X^2]=√(144-24X)=6√5-6
144-24X=36(6-2√5)=216-72√5
24X=72√5-72
X=3√5-3
点P是角C平分线与AB的交点
AC=6√5,[AC^2=AB^2+BC^2=144+36=180=9*4*5]
设PB=X,作PD⊥AC于D,PD=PB=X
AP=12-X
AD^2=AP^2-PD^2
AD=√[(12-X)^2-X^2]=√(144-24X)=6√5-6
144-24X=36(6-2√5)=216-72√5
24X=72√5-72
X=3√5-3