24题,如图
1个回答

∵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