【導(dǎo)讀】,D是AB邊上的中點(diǎn),將△ABC沿過D的直線折疊,使點(diǎn)A落在BC上F處,若∠B=50°,,在△ABC中,AB=AC,AD是△ABC的角平分線,DE⊥AB,DF⊥AC,垂足分別為E,F(xiàn).則下列四個(gè)結(jié)論:①AD上任意一點(diǎn)到點(diǎn)C,B的距離相等;②AD上任意一點(diǎn)到邊AB,,在△ABC中,∠ABC=90°,D是△ABC內(nèi)一點(diǎn),將△ADB繞點(diǎn)B旋轉(zhuǎn)至△BD′C,