1.We offered hin our congratulations( )his passing the colledge entrance exams.a.at b.on c.for d.of2.-Would you like to go shopping tomorrow?-If Tom does,( )a.so do I b.so shall I c.so do I d.so I shall3.在矩形ABCD中,AC,BD交于点O,AE平分角BA
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1.We offered hin our congratulations( )his passing the colledge entrance exams.a.at b.on c.for d.of2.-Would you like to go shopping tomorrow?-If Tom does,( )a.so do I b.so shall I c.so do I d.so I shall3.在矩形ABCD中,AC,BD交于点O,AE平分角BA
1.We offered hin our congratulations( )his passing the colledge entrance exams.
a.at b.on c.for d.of
2.-Would you like to go shopping tomorrow?
-If Tom does,( )
a.so do I b.so shall I c.so do I d.so I shall
3.在矩形ABCD中,AC,BD交于点O,AE平分角BAD.若角EAO=15度,求角BOE的度数
4.已知,在平行四边形ABCD中,以AC为斜边作直角三角形ACE,且角BED为直角
求证:四边形ABCD是矩形
图没有,不过如果想拿到分的话,就自己画吧,一定能画的出来的.而且,
1.We offered hin our congratulations( )his passing the colledge entrance exams.a.at b.on c.for d.of2.-Would you like to go shopping tomorrow?-If Tom does,( )a.so do I b.so shall I c.so do I d.so I shall3.在矩形ABCD中,AC,BD交于点O,AE平分角BA
1 C
2 So do I
3因为矩形 ∠BAE=45°∠EAO=15°
所以∠BAO=60° 所以AB=AO=BO
因为AE=√2*AO AC=2AO ∠EAC=15°
则AO/AE=AE/AC=√2/2
所以△AOE≌△AEC
所以∠AOE=135°
所以∠BOE=135°-60°=75°
4设AC BD交点为O 连接OE
因为∠AEC=∠BED=90° O为AC BD 中点
所以OE=0A=OD=1/2AC=1/2BD
所以ABCD为矩形
哇~