挑战习题
1/5单选题
难度:

1.在正方形ABCD中,E为CD上一点,F为BC上一点,且EF=BF+DE,则∠EAF的度数为(  )
A 30°
B 60°
C 45°
D 小于60°
提示1:
DQrlu7bplb9FQuS9v+W+l0JHPURG77yM5piT6K+B4pazQUJH4omM4pazQURG77yIU0FT77yJ5Y+v5b6XQUY9QUfvvIzov5vogIzmsYLor4HilrNBRUfiiYzilrNBRUblj6/lvpfiiKBFQUc94oigRUFG77yM5YaN5rGC5Ye64oigRUFHK+KIoEVBRj05MMKw5Y2z5Y+v6Kej6aKYLiANCg==
正确答案:Qw==
6Kej77ya5bu26ZW/RULkvb/lvpdCRz1ERu+8jOi/nuaOpUFH77yMPGJyPjxpbWcgd2lkdGg9MTQ1IGhlaWdodD0xMDUgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC82MS9DNi9yQkFDRkZPVklxSEJCNzdpQUFBVDB5dWc4Y0k4NzgucG5nIiA+PGJyPuWcqOKWs0FCR+WSjOKWs0FERuS4re+8jDxicj48aW1nIHdpZHRoPTE0OCBoZWlnaHQ9ODMgc3JjPSJodHRwczovL3AyLnFpbmdndW8uY29tL0cxL00wMC82MS9DNi9yQkFDRkZPVklxSFFQNTFNQUFBRVpIU1ktaGMzNTcucG5nIj7vvIw8YnI+4oi04pazQUJH4omM4pazQURG77yIU0FT77yJ77yMPGJyPuKItOKIoERBRj3iiKBCQUfvvIxBRj1BR++8jDxicj7lj4jiiLVFRj1ERitCRT1FQitCRz1FR++8jEFFPUFF77yMPGJyPuWcqOKWs0FFR+WSjOKWs0FFRuS4re+8jDxicj48aW1nIHdpZHRoPTY2IGhlaWdodD04MyBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwLzlEL0REL3JCQUNFMU9WSXFHUk51T1dBQUFEUmxDTlBrRTg3NS5wbmciPu+8jDxicj7iiLTilrNBRUfiiYzilrNBRUbvvIhTU1PvvInvvIw8YnI+4oi04oigRUFHPeKIoEVBRu+8jDxicj7iiLXiiKBEQUYr4oigRUFGK+KIoEJBRT05MMKwPGJyPuKItOKIoEVBRyviiKBFQUY9OTDCsO+8jDxicj7iiLTiiKBFQUY9NDXCsC4gPGJyPuaVhemAiUMuIA==