( 1)、AB=AC、AD=AE、∠BAD=∠BAC-∠DAC=∠DAE-∠DAC=∠CAE
So: triangle BAD is congruent with triangle CAE, so ∠B=∠ACE.
(2) From (1), it is known that ∠ ace = ∠ b = 45,
(a): ef = EC, then: ∠ EFC = 45 = ∠ CAE+∠ AEF = 45+∠ CAE. Get ∠ CAE = 0, when C and E coincide, D and B coincide, ∠ Bad = 0, which is irrelevant at this time.
(b): CE = CF,∠ CFE = 67.5 = ∠ CAE+∠ AEF = 45+∠ CAE,∠ CAE = 12.5,∠ Bad = 65438。
(c): cf = ef,∠ cfe = 90 = ∠ CAE+∠ AEF = 45+∠ CAE,∠ CAE = 45,∠ bad = 45。
To sum up: ∠ bad = 45 or 12.5.