如图,EF∥AD,∠1=∠2.说明:∠DGA+∠BAC=180°.请将说明过程填写完成.
解:∵EF∥AD,(已知)
∴∠2={#blank#}1{#/blank#}.({#blank#}2{#/blank#})
又∵∠1=∠2,({#blank#}3{#/blank#})
∴∠1=∠3,({#blank#}4{#/blank#})
∴AB∥{#blank#}5{#/blank#},({#blank#}6{#/blank#})
∴∠DGA+∠BAC=180°.({#blank#}7{#/blank#})
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