25.在Rt△ABC中,∠BAC=90°,
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(1)若∠DAE=90°,AD=AE(A,D,E按逆時(shí)針排列).
①如圖1,當(dāng)點(diǎn)D在邊BC上時(shí),請(qǐng)直接寫(xiě)出BD與CE的數(shù)量關(guān)系和位置關(guān)系;
②如圖2,當(dāng)點(diǎn)D在△ABC外部時(shí)(點(diǎn)E,B,C不在同一條直線上),且BE=BC,求證:CD=DE;
(2)點(diǎn)D在△ABC外部,若
,且CD⊥BD于點(diǎn)D,請(qǐng)直接寫(xiě)出AD的長(zhǎng).