AB=AC
AB²=BD×CE
AB×AC =BD ×CE
AB:CE=BD:AC
∠ABC=∠ACB
∠ABD=∠ACE
△ABD∽△ECA
(2)∠DAE=∠BAC +∠DAB +∠EAC =∠BAC +∠E +∠CAE =∠BAC +∠ACB=40+70=110
AB=AC
AB²=BD×CE
AB×AC =BD ×CE
AB:CE=BD:AC
∠ABC=∠ACB
∠ABD=∠ACE
△ABD∽△ECA
(2)∠DAE=∠BAC +∠DAB +∠EAC =∠BAC +∠E +∠CAE =∠BAC +∠ACB=40+70=110