共50条信息
如图,\(AB/\!/\)平面\(\alpha /\!/\)平面\(\beta \),过\(A\),\(B\)的直线\(m\),\(n\)分别交\(\alpha \)、\(\beta \)于\(C\),\(E\)和\(D\),\(F\),若\(AC=2\),\(CE=3\),\(BF=4\),则\(BD\)的长为____________.
\((1)\)求\(C\)和\(BD;\)
\((2)\)求四边形\(ABCD\)的面积.
在如图所示的几何体中,四边形\(DCEF\)为正方形,四边形\(ABCD\)为等腰梯形,\(AB/\!/CD,AC=\sqrt{3},AB=2BC=2\),且\(AC\bot FB\).
\((\)Ⅰ\()\)求证:平面\(EAC\bot \)平面\(FCB\);
\((\)Ⅱ\()\)若线段\(AC\)上存在点\(M\),使\(AE/\!/\)平面\(FDM\),求\(\dfrac{AM}{MC}\)的值.
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