优优班--学霸训练营 > 知识点挑题
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            • 1. 在直三棱柱\(ABC-A_{1}B_{1}C_{1}\)中,底面为直角三角形,\(∠ACB=90^{\circ}\),\(AC=6\),\(BC=CC_{1}= \sqrt{2}\),\(P\)是\(BC_{1}\)上一动点,如图所示,求\(CP+PA_{1}\)的最小值.

            • 2. 如图,在棱长为\(1\)的正方体\(ABCD-A_{1}B_{1}C_{1}D_{1}\)中,\(P\)、\(Q\)分别是线段\(CC_{1}\),\(BD\)上的点,\(R\)是直线\(AD\)上的点,满足\(PQ/\!/\)平面\(ABC_{1}D_{1}\),\(PQ⊥RQ\),则\(|PR|\)的最小值是\((\)  \()\)
              A.\( \dfrac { \sqrt {42}}{6}\)
              B.\( \dfrac { \sqrt {30}}{5}\)
              C.\( \dfrac { \sqrt {5}}{2}\)
              D.\( \dfrac {2 \sqrt {3}}{3}\)
            • 3.

              在直三棱柱\(A_{1}B_{1}C_{1}-ABC\)中,底面\(ABC\)为直角三角形,\(\angle BAC=\dfrac{{ }\!\!\pi\!\!{ }}{2}\) ,\(AB=AC=AA_{1}=1.\)已知\(G\)与\(E\)分别为\(A_{1}B_{1}\)和\(CC_{1}\)的中点,\(D\)与\(F\)分别为线段\(AC\)和\(AB\)上的动点\((\)不包括端点\().\)若\(GD⊥EF\),则线段\(DF\)的长度的最小值为\((\)    \()\)

              A.\(\dfrac{\sqrt{5}}{5}\)
              B.\(\sqrt{5}\)
              C.\(1\)
              D.\(\dfrac{\sqrt{3}}{3}\)
            • 4.

              如图所示,在棱长为\(2\)的正方体\(ABCD—A_{1}B_{1}C_{1}D_{1}\)中,\(E\)为棱\(CC_{1}\)的中点,点\(P\),\(Q\)分别为正方形\(A_{1}B_{1}C_{1}D_{1}\)内\((\)含边界\()\)和线段\(B_{1}C\)上的动点,则\(\triangle PEQ\)周长的最小值为________.

            • 5. 在正四棱柱\(ABCD-A_{1}B_{1}C_{1}D_{1}\)中,\(AB=1,AA_{1}= \sqrt {3}\),\(E\)为\(AB\)上一个动点,则\(D_{1}E+CE\)的最小值为\((\)  \()\)
              A.\(2 \sqrt {2}\)
              B.\( \sqrt {10}\)
              C.\( \sqrt {5}+1\)
              D.\(x\leqslant y\)
            • 6.

              \(6.\)如图,在正方形\(ABCD\)中,\(E\)、\(F\)分别是\(BC\)、\(CD\)的中点,\(G\)是\(EF\)的中点,现在沿\(AE\)、\(AF\)及\(EF\)把这个正方形折成一个空间图形,使\(B\)、\(C\)、\(D\)三点重合,重合后的点记为\(H\),那么,在这个空间图形中必有\((\)  \()\)

              A.\(AG⊥\triangle EFH\)所在平面      
              B.\(AH⊥\triangle EFH\)所在平面
              C.\(HF⊥\triangle AEF\)所在平面       
              D.\(HG⊥\triangle AEF\)所在平面
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