Question

如图，△ABC≌△ADE，且∠CAD=10°，∠B=∠D=25°，∠EAB=120°，求∠DFB和∠DGB的度数

如图，△ABC≌△ADE，且∠CAD=10°，∠B=∠D=25°，∠EAB=120°，求∠DFB和∠DGB的度数．

Answer 1

∵△ABC≌△ADE，
∴∠DAE=∠BAC=

1

2

（∠EAB-∠CAD）=

1

2

(120°?10°)＝55°．
∴∠DFB=∠FAB+∠B=∠FAC+∠CAB+∠B=10°+55°+25°=90°
∠DGB=∠DFB-∠D=90°-25°=65°．
综上所述：∠DFB=90°，∠DGB=65°．