Question

已知,如图所示.△ABC中,∠ABC＝45°,CD⊥AB于D,BE平分∠ABC,且BE⊥AC于E,与CD相交于点F,H是

Answer 1

1、CD⊥AB,∠ABC＝45°,则BD=CD,

∠ADC＝∠AEB＝90°,则,∠A=∠DFB,那么△BDF与△ADC的三个角相等,BD=CD

可证△BDF与△ADC全等,BF＝AC

2、BE平分∠ABC,且BE⊥AC,可知E平分CA,而BF＝AC,所以CE＝½AC＝½BF