共50条信息
如图,\(AC\)是\(□\)\(ABCD\)的对角线,在\(AD\)边上取一点\(F\),连接\(BF\)交\(AC\)于点\(E\),并延长\(BF\)交\(CD\)的延长线于点\(G\).
\((1)\)若\(∠ABF=∠ACF\),求证:\(CE^{2}=EF⋅EG\);
\((2)\)若\(DG=DC\),\(BE= 4\),求\(CE\)的长.
如图,在平面直角坐标系中,已知点\(A(6,8)\),将\(OA\)绕坐标原点\(O\)逆时针旋转\(90^{\circ}\)至\(OA′\),则点\(A′\)的坐标 是_________.
如图,在四边形\(ABCD\)中,\(AB=BC\),对角线\(BD\)平分\(∠ABC\),\(P\)是\(BD\)上一点,过点\(P\)作\(PM⊥AD\),\(PN⊥CD\),垂足分别为\(M\)、\(N\).
\((1)\)求证:\(∠\)\(ADB=∠CDB\);
\((2)\)若\(∠ADC=90^{\circ}\),求证:四边形\(MPND\)是正方形.
如图,在\(\triangle ABC\)中,\(AB=AC\),\(BE=CD\),\(BD=CF\),则\(∠EDF=)\)( )
己知正方形\(①\)、\(②\)在直线上,正方形\(③\)如图放置,若正方形\(①\)、\(②\)的面积分别为\(81cm^{2}\)和\(144cm^{2}\),则正方形\(③\)的边长为\((\) \()\)
如图,已知四边形\(ABCD\)是平行四边形,点\(E\)、\(B\)、\(D\)、\(F\)在同一直线上,且\(BE=DF.\)求证:\(AE=CF\).
如图,\(E\),\(F\)分别是矩形\(ABCD\)的边\(AD\),\(AB\)上的点,若\(EF=EC\),且\(EF⊥EC\).
\((1)\)求证:\(AE=DC\);
\((2)\)已知\(DC= \sqrt{2} \),直接写出\(BE\)的长.
如图,\(CD\)\(=\)\(BE\),\(DG\)\(⊥\)\(BC\)于\(G\),\(EF\)\(⊥\)\(BG\)交\(BC\)于\(F\),且\(DG\)\(=\)\(EF\).
\((1)\)求证:\(\triangle \)\(DGC\)≌\(\triangle \)\(EFB\);
\((2)\)求证:\(OB\)\(=\)\(OC\)
把一大一小两个等腰直角三角板\((\)即\(EC=CD\),\(AC=BC)\)如图放置,点\(D\)在\(BC\)上,连结\(BE\),\(AD\),\(AD\)的延长线交\(BE\)于点\(F\).
求证:\((1)ΔACD\)≌\(ΔBCE\)
\((2)AF⊥BE.\)
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