在数学家吴文俊主编的《“九章算术”与刘徽》一书中,小宇同学看到一道有趣的数学问题:古代数学家刘徽使用“出入相补”原理,即割补法,把筝形转化为与之面积相等的矩形,从而得到“筝形的面积等于其对角线乘积之半”.(说明:一条对角线垂直平分另一条对角线的四边形是筝形)请根据下图完成这个数学问题的证明过程.
![](https://img.xkw.com/dksih/QBM/2020/7/23/2512232057307136/2512844346433536/STEM/bd06127db74f4116a1cbcd24e18288d7.png?resizew=117)
更新时间:2020-07-24 16:17:49
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【知识点】 根据矩形的性质与判定求面积
相似题推荐
解答题-证明题
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较易
(0.85)
【推荐1】如图,已知矩形
中,对角线
、
相交于点
,过点
作
,交
的延长线于点
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/23/ccf64e25-726c-4896-8cc9-965169f7aaa4.png?resizew=205)
(1)求证:
;
(2)若
,
,求矩形
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/684d328b02462aa25a936d1c83eee4fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/23/ccf64e25-726c-4896-8cc9-965169f7aaa4.png?resizew=205)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/934a9508c176f44bf58f88715bd98f76.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04453ddc09098fd241a5011aba9659b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65ff13b4da65c7da3d898ba58e967b24.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
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解答题-问答题
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较易
(0.85)
【推荐2】如图是由边长为1的小正方形组成的网格,每个小正方形的顶点叫做格点,点
、
均在格点上,仅用无刻度的直尺完成画图,请按步骤完成下列问题.
![](https://img.xkw.com/dksih/QBM/2021/7/6/2758635263426560/2767566284972032/STEM/2d32ad52-fd6a-407f-a498-bad914434d14.png)
(1)
______;
(2)在格点上找到点
,
,连接
,
,
,使四边形
是长与宽之比为2∶1的矩形;
(3)在格点上找一点
,连接
,使得过
的直线平分矩形
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://img.xkw.com/dksih/QBM/2021/7/6/2758635263426560/2767566284972032/STEM/2d32ad52-fd6a-407f-a498-bad914434d14.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c26a46e7879436d532af3f4b6e258a81.png)
(2)在格点上找到点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f96461af9193d5d7867ddf8fcbefcaec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(3)在格点上找一点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
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