设FG与NE交点为H点,AB与NE的交点I点
在三角形HNG中:∠G+∠HNG+∠NHG=180°
∠HNG=∠AIE=∠IHM+∠ IMH= ( ∠ E + ∠EMF) +∠ IMH =∠ E + (∠EMF +∠ IMH ) =
∠ E+ ∠AME
∠NHG =∠IHM= ∠ E + ∠EMF= ∠ E + 1/2∠AME
所以:∠G+∠HNG+∠NHG=∠G+(∠ E+ ∠AME)+(∠ E + 1/2∠AME)=180°
( ∠G+2∠ E)+3/2 ∠AME=180°
90°+3/2 ∠AME=180°
∠AME=60°