Question

如图,∠A=15°,AB=BC=CD=DE=EF,则∠EDF等于____°

Answer 1

∠EDF=∠A+∠AED=∠A+∠ECD=∠A+∠A+∠CDB=2∠A+∠CBA=2∠A+∠A+∠ACB=4∠A=60°。