取AB,AC中点FG连接MF,PF,NG,PG
AFPG平行四边形 FPG=BAC=120
MFP全等PGN MPF=PNG MFP=PNG=120 FMP=GPN
所以GPN+MPF= FMP+MPF=180-120=60
∠MPN=FGP-(GPN+MPF)=120-60=60
取AB,AC中点FG连接MF,PF,NG,PG
AFPG平行四边形 FPG=BAC=120
MFP全等PGN MPF=PNG MFP=PNG=120 FMP=GPN
所以GPN+MPF= FMP+MPF=180-120=60
∠MPN=FGP-(GPN+MPF)=120-60=60