24.如圖,正方形ABCD中,點(diǎn)M在邊BC上運(yùn)動,點(diǎn)E是AM的中點(diǎn),連接ED,EC.
(1)求證:△EAD≌△EBC;
(2)將BE繞點(diǎn)E逆時針旋轉(zhuǎn),使點(diǎn)B的對應(yīng)點(diǎn)B'落在AC上,連接MB′,當(dāng)點(diǎn)M在邊BC上運(yùn)動時(點(diǎn)M不與B,C重合),判斷△CMB'的形狀,并說明理由;
(3)在(2)的條件下,當(dāng)∠CEM=45°時,求∠DEB'的度數(shù).