1 . 请根据所给的图形,把空白之处填写完整.
(1)直线与平面平行的性质定理(请用符号语言作答).
如图①,已知:a∥α,______ ,
求证:_____ .
(2)平面与平面垂直的性质定理的证明.
如图②,已知:α⊥β,AB∩CD=B,α∩β=CD,____ ,____ ,
求证:AB⊥β.
证明:在β内引直线____ ,垂足为B,则____ 是二面角____ 的平面角,
由α⊥β,知____ ,又AB⊥CD,BE和CD是β内的两条____ 直线,所以AB⊥β.
(1)直线与平面平行的性质定理(请用符号语言作答).
如图①,已知:a∥α,
求证:
(2)平面与平面垂直的性质定理的证明.
如图②,已知:α⊥β,AB∩CD=B,α∩β=CD,
求证:AB⊥β.
证明:在β内引直线
由α⊥β,知
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/25/aa46a720-1294-48a4-b049-f071de3c6ba7.png?resizew=266)
您最近一年使用:0次
解题方法
2 . 如图,在正方体
中,
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/4/6c0d410b-9639-4583-88dd-cf29de37c0da.png?resizew=176)
(1)求证:
平面
;
(2)求证:平面
平面
.(只需在下面横线上填写给出的如下结论的序号 :①
平面
,②
平面
,③
,④
,⑤
)
证明:(1)设
,连接
.因为底面
是正方形,所以
为
的中点,又
是
的中点,所以_________.因为
平面
,____________,所以
平面
.
(2)因为
平面
平面
,所以___________,因为底面
是正方形,所以_______,又因为
平面
平面
,所以_________.又
平面
,所以平面
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/4/6c0d410b-9639-4583-88dd-cf29de37c0da.png?resizew=176)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f11f1840eb8b17e7b07c3fe7e987a9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca48c18021e7be4bbb3e95576e1c1b5f.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/077dcbb7a11d1ab7c9644bd1fe9b4368.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca48c18021e7be4bbb3e95576e1c1b5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc78a86b12ba0b4553135a3a635fc418.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cffb30e92f06a10b82da994fa304d2c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca48c18021e7be4bbb3e95576e1c1b5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0d7af0ab753d5017928560ae47de106.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70734a8e672376bb0bd1522e229f86a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/105cdc325328b683456c1443f6296f8b.png)
证明:(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a23f01af749100e1888bba06268843db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f90c780dac29ff8b7df5881d3b33abab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d97dc3b752832906de41447bb58a341.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b2104bb78c7d7d58c1f51a25daa8086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca48c18021e7be4bbb3e95576e1c1b5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f11f1840eb8b17e7b07c3fe7e987a9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca48c18021e7be4bbb3e95576e1c1b5f.png)
(2)因为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ddbb0422a136f45653c8c369f2d75fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9263a4c1054ec924e900a1544180a83b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22bc82cd42e79c932abe14fa79265ed3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a03f5a663501d8fa265fdb593ed4bfab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc78a86b12ba0b4553135a3a635fc418.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f196748dc6a0d0bd9e9e4dd30ac4ed0e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca48c18021e7be4bbb3e95576e1c1b5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/077dcbb7a11d1ab7c9644bd1fe9b4368.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca48c18021e7be4bbb3e95576e1c1b5f.png)
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3 . 证明面面平行的一般方法有哪些?
________
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