如图,在直角三角形ABC中,AB=AC,角BAC=90度,角1=角2,CE垂直于BD的延长线于点E,试说明BD=2CE的理由

⊥≌∽∵∴∠△
过C做CH垂直AC;交AF延长线于H;
∵∠BAC=90°;AF⊥BD;
∴∠ABD=∠EAD=90-∠ADB;
AB=AC;
∠BAD=∠ACH=90°;
∴△ABD≌△CAH;
∴HC=AD=DC=1/2AC=1/2AB;
∵∠BAC=90°;CH⊥AC;
∴AB//CH;
∴CF/BF=CH/AB=1/2;
CF/CF+BF=CF/BC=1/2+1=1/3;
CF=1/3BC;
BC=3根号2;
∴CF=根号2;