Question

如图:∠AEF=90°,AB=BC=CD=DE=EF,则∠EAF=_____

Answer 1

∵AB=BC=CD=DE=EF

∴∠A=∠BCA

∠CBD=∠CDB=∠A+∠ACB=2∠A

∠DCE=∠DEC=∠A+∠CDB=3∠A

∠EDF=∠EFD=∠A+∠DEC=4∠A

∵∠AEF=90°

∴∠A+∠EFD=90°

即∠A+4∠A=90°

∵∠A=18°