问题
选择题
在正方形ABCD的边BC的延长线上取一点E,使CE=AC,AE与CD交于点F,那么∠AFC的度数为( )
A.105°
B.112.5°
C.135°
D.120°
答案
∵四边形ABCD是正方形,
∴∠ACB=∠2=45°.
∵AC=CE,
∴∠1=∠E=22.5°.
∴∠AFC=180°-45°-22.5°=112.5°.
故选B.
在正方形ABCD的边BC的延长线上取一点E,使CE=AC,AE与CD交于点F,那么∠AFC的度数为( )
A.105°
B.112.5°
C.135°
D.120°
∵四边形ABCD是正方形,
∴∠ACB=∠2=45°.
∵AC=CE,
∴∠1=∠E=22.5°.
∴∠AFC=180°-45°-22.5°=112.5°.
故选B.