连接BE,令DE,BC交于G
∵∠DGC=∠BGE
∴180°-∠DGC=180°-∠BGE
即∠D+∠C=∠CBE+∠DEB
∠A+∠B+∠C+∠D+∠E+∠F=∠A+(∠ABC+∠CBE)+(∠DEB+∠FED)+∠F
=∠A+∠ABE+∠FEB+∠F
=180°*(4-2)
=360°满意请采纳