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            • 1.

              四边形\(ABCD\)的内角\(A\)与\(C\)互补,\(AB=1\),\(BC=3\),\(CD=DA=2\).

              \((1)\)求\(C\)和\(BD;\)

              \((2)\)求四边形\(ABCD\)的面积.

            • 2. 如图在\(\triangle ABC\)中,\(AB= \dfrac {3 \sqrt {6}}{2}\),\(CD=5\),\(∠ABC=45^{\circ}\),\(∠ACB=60^{\circ}\),则\(AD=\)______.
            • 3.

              在\(Rt\triangle \)\(ABC\)中,\(∠\)\(BAC=\)\(90^{\circ}\),\(AB=\)\(1\),\(BC=\)\(2\)\(BC\)边上任取一点\(M\),则\(∠\)\(AMB\)\(\geqslant 90^{\circ}\)的概率为                   

            • 4.
              如图,在\(\triangle ABC\)中,\(∠ABC=90^{\circ}\),\(BD⊥AC\),\(D\)为垂足,\(E\)为\(BC\)的中点,求证:\(∠EDC=∠ABD\).
            • 5.
              如图,正方形\(ABCD\)中,以\(D\)为圆心、\(DA\)为半径的圆弧与以\(BC\)为直径的半圆\(O\)交于点\(F\),连接\(CF\)并延长交\(AB\)于点\(E\).
              \((\)Ⅰ\()\)求证:\(AE=EB\);
              \((\)Ⅱ\()\)若\(EF⋅FC= \dfrac {4}{5}\),求正方形\(ABCD\)的面积.
            • 6.
              选修\(4—1\):几何证明选讲

              如图,\(AC\)是圆\(O\)的切线,\(A\)是切点,\(AD⊥OE\)于\(D\),割线\(EC\)交圆\(O\)于\(B\)、\(C\)两点.

              \((1)\)证明:\(O\)、\(D\)、\(B\)、\(C\)四点共圆;

              \((2)\)设\(∠DBC=50^{\circ}\),\(∠ODC=30^{\circ}\),求\(∠OEC\)的大小.

            • 7.
              选做题:平面几何
              已知在\(\triangle ABC\)中,\(AB=AC\),以\(AB\)为直径的\(⊙O\)交\(BC\)于\(D\),过\(D\)点作\(⊙O\)的切线交\(AC\)于\(E\).
              求证:\((1)DE⊥AC\);\(\)
              \((2)BD^{2}=CE⋅CA\).
            • 8.
              \(\triangle ABC\)中,\(∠BAC=90^{\circ}\),\(AD⊥BC\),垂足为\(D.\)若\(BC=m\),\(∠B=α\),则\(AD\)长为\((\)  \()\)
              A.\(m\sin ^{2}α\)
              B.\(m\cos ^{2}α\)
              C.\(m\sin α\cos α\)
              D.\(m\sin α\tan α\)
            • 9.
              如图, ,且 ,则 \((\)  \()\)

              A.     
              B.    
              C.     
              D. 
            • 10.
              如图所示,在平面四边形\(ABCD\)中,\(AB⊥AD\),\(∠ADC= \dfrac {2π}{3}\),\(E\)为\(AD\)边上一点,\(CE= \sqrt {7}\),\(DE=1\),\(AE=2\),\(∠BEC= \dfrac {π}{3}\).
              \((\)Ⅰ\()\)求\(\sin ∠CED\)的值;
              \((\)Ⅱ\()\)求\(BE\)的长.
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