来自励惠国的问题
如图,BE⊥AC、CF⊥AB于点E、F,BE与CF交于点D,DE=DF,连接AD.求证:(1)∠FAD=∠EAD(2)BD=CD.
如图,BE⊥AC、CF⊥AB于点E、F,BE与CF交于点D,DE=DF,连接AD.
求证:(1)∠FAD=∠EAD
(2)BD=CD.
1回答
2020-03-20 13:25
如图,BE⊥AC、CF⊥AB于点E、F,BE与CF交于点D,DE=DF,连接AD.求证:(1)∠FAD=∠EAD(2)BD=CD.
如图,BE⊥AC、CF⊥AB于点E、F,BE与CF交于点D,DE=DF,连接AD.
求证:(1)∠FAD=∠EAD
(2)BD=CD.
证明:(1)∵BE⊥AC、CF⊥AB,DE=DF,∴AD是∠BAC的平分线,∴∠FAD=∠EAD;(2)∵△ADF与△ADE是直角三角形,DE=DF,AD=AD,∴Rt△ADF≌Rt△ADE,∴∠ADF=∠ADE,∵∠BDF=∠CDE,∴∠ADF+∠BDF=∠ADF+∠CDE,即∠...