Proof: Take a little M from AB to make am = EC, and connect me.
∴BM=BE.∴∠BME=45。 ∴∠AME= 135。
∫CF is the bisector of the outer corner,
∴∠DCF=45。 ∴∠ECF= 135。
∴∠AME=∠ECF.
∠∠AEB+∠BAE = 90,∠AEB+CEF=90,
∴∠BAE=∠CEF.
∴△AME≌△BCF(ASA).
∴AE=EF.
(2) correct.
Proof: Take a little n on the extension line of BA, make an = ce, and then connect ne.
∴BN=BE.
∴∠N=∠FCE=45。
The quadrilateral ABCD is a square,
∴AD‖BE.
∴∠DAE=∠BEA.
∴∠NAE=∠CEF.
∴△ANE≌△ECF(ASA).
∴AE=EF.