由条件可得:∠AEC=∠BAE+∠DCE
∠AFC=360°-∠BAF-∠DCF
=360°-4(∠BAE+∠DCE)
=360°-4∠AEC
所以:∠AFC+4∠AEC=360°
∠AFC=360度-4∠AEC
证明:∠AFC=360°—4∠AEC
∵∠BAE+∠DCE=∠AEC
∠FAE=3∠BAE同理∠FCE=3∠ECD
∴∠FAE+∠FCE=3(∠BAE+∠DCE)=3∠AEC
∵四边形AFCE的内角和为360°
∴∠AFC+∠FAE+∠FCE+∠AEC=∠AFC+4∠AEC=360°
∴∠AFC=360°—4∠AEC
应该对吧,好久没有做这样的题了,希望给个好评价!!!O(∩_∩)O~
∠AEC=180-∠CAE-∠ACE
=180-(90-∠BAE)-(90-∠DCE)
=∠BAE+∠DCE
又∠AEC+∠FAE+∠FCE+∠AFC=360
∠AEC+(∠BAF-∠BAE)+(∠DCF-∠DCE)+∠AFC=360
∠AEC+3∠BAE+3∠DCE+∠AFC=360
∠AEC+3(∠BAE+∠DCE)+∠AFC=360
4∠AEC+∠AFC=360
解:过E点做的ab平行线en(n在e左侧),因为ab//cd,所以en//ab//cd.。所以∠bae=∠aen,因为
∠baf=4∠bae,所以∠fae=3∠bae=3∠aen,同理∠fce=3∠ecd=3∠cen.又因为
∠afc+∠aec+∠fae+∠fce=360'∠
∠afc+∠aec+3∠aen+3∠cen=∠afc+∠aec+3∠aec=∠afc+4∠aec=360
故他们的数量关系为=∠afc+4∠aec=360