如图,在△ABC中,AB=AC,点D、E、F分别在BC、AB、AC边上,且BE=CF,AD+EC=AB.
(1)△DEF是 三角形;当∠A=40°时,∠DEF的度数为 °;
(2)请你猜想:当∠A为多少度时,∠EDF+∠EFD=120°,并请说明理由.
(1)△DEF是 三角形;当∠A=40°时,∠DEF的度数为 °;
(2)请你猜想:当∠A为多少度时,∠EDF+∠EFD=120°,并请说明理由.
![](https://img.xkw.com/dksih/QBM/2021/4/15/2700401416527872/2700932109819904/STEM/f9f365ea7a3f4a5eb926145568c406a4.png?resizew=119)
更新时间:2021-04-16 10:03:21
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真题
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【推荐2】已知:如图,点A,C,D,B在同一条直线上,AC=BD,AE=BF,∠A=∠B.求证:∠E=∠F.
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解答题-证明题
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