26.如圖,在△ABC中,AB=AC,∠ABC=∠ACB,∠BAC=α(0°<α<90°),D為射線BC上一動(dòng)點(diǎn)(不與點(diǎn)B、C重合),在AD的右側(cè)作△ADE,使得AD=AE,∠BAC=∠DAE,連接CE.
(1)若點(diǎn)D在線段BC上,
①求證:△BAD≌△CAE;
②若CE∥AB,求證:∠BAC=∠ACB=∠B,并猜想AB,CD,CE之間的數(shù)量關(guān)系,直接寫出結(jié)論;
(2)點(diǎn)D的運(yùn)動(dòng)過程中,當(dāng)DE垂直于△ABC的某邊時(shí),直接寫出∠DEC的度數(shù).(用含α的代數(shù)式表示)
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