∵正方形ABCD,BE⊥ED,EA⊥FA,
∴AB=AD=CD=BC,∠BAD=∠EAF=∠90°=∠BEF,
∵∠APD=∠EPB,
∴∠EAB=∠DAF,∠EBA=∠ADP,
∵AB=AD,
∴△ABE≌△ADF
∴△AEF是直角三角形
∵AE=2
∴EF=√4 4=2√2
(2)设正方形的边长为2a,则AP=PB=a
∴PD=√(5)a
RT△PEB∼RT△PAD
PE/PA=PB/PD 则PE/a=a/√(5)a
∴PE=a/√(5)
∴BE=√((a^2)-((a/√(5))^2))=2√(5)a/5
∴PE BE=3√(5)a/5
易证△AFD≅△AEB
∴DF=BE
∴PF=PD-FD=PD-BE=√(5)a-2√(5)a/5=3√(5)a/5
∴PF=EP EB