如图,在△ABC中,AE是中线,AD是角平分线,AF是高,填空: (1)BE=_=1/2_ (2)∠BAD=_1/2_ (3)∠AFB=_=90° (4)S△ABC=_S△ABE.

问题描述:

如图,在△ABC中,AE是中线,AD是角平分线,AF是高,填空:
(1)BE=______=

1
2
______
(2)∠BAD=______
1
2
______
(3)∠AFB=______=90°
(4)S△ABC=______S△ABE

(1)∵AE是中线,
∴BE=CE=

1
2
BC,
(2)∵AD是角平分线,
∴∠BAD=∠CAD=
1
2
∠BAC,
(3)∵AF是高,
∴∠AFB=∠AFC=90°,
(4)S△ABC=
BC•AF
2

S△ABE=
BE•AF
2

∵BC=2BE,
∴S△ABC=2S△ABE
故答案为CE,BC,∠CAD,∠BAC,∠AFC,2.