1 . 在△ABC中,若角A,B,C的对边分别为a,b,c,则△ABC的面积
,其中
,称该公式为海伦公式,该公式可推广到平面四边形:若四边形ABCD内接于圆E,且四边长分别为a,b,c,d,则四边形ABCD的面积
,其中
,若面积为
的四边形ABCD内接于圆E,
,
,点C,D在x轴上方,且
,
,则圆E的标准方程为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8dab06d51bc8c3b659ba7abaa67c6f2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0f2d50ca5cc415bf6721faf2221d626.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3f3d5d27c3574355097050c813ebe8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/575008e0b065f0d535251a041203f99f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e7dc603317eb90974c75efec9f02b1b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0929421a6188c3122442866b0b85a5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54fe2c124d5bbbbe666ee145cd454b6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89488b28105f7612b3da3b90c1b935e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c7fcbc06a3269890bb9971a48ac2d35.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
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2 . 我国许多地方都有风格迥异的古塔.现在在某塔底共线三点
处分别测得塔顶P点的仰角为
,
,
,且
,设该塔高为
,示意图如图,则该塔高![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5516a7ad03e49c26d9a6303365664fb.png)
________ m.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ac09dc1ca2cdd7aef28c218763d3e4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1e5fa72f2878b476bc57f0df12d6555.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d5bca00fa20e6e80480b9d06d2e52ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de303eb9ff8ccfc0b6ebdf8380456fd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef49a3ca580a144cc65a609c167facc1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5516a7ad03e49c26d9a6303365664fb.png)
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解题方法
3 . 在
中,已知
,N是BC的中点,M是
的外心.
(1)若
,求AN的长.
(2)当
变化时,猜一个理想角
,使得易求
的值,并证明对任意的
,
为定值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b22c64cfb042014a6b538ab1a0276d14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fffa3d9c32da53b0ea0c338012ea20c.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1905448d38b7465423fe637d700f1552.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1905448d38b7465423fe637d700f1552.png)
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解题方法
4 . 如图,一个加盖密封的漏斗的上面部分是一个正方体,下面部分是一个正四棱锥,该几何体所有棱长均为2米.
(2)若一只蚂蚁沿漏斗表面从点
爬到点
,求它爬过的最短路径的长;
(3)将图中正方形
水平放置,在由斜二测画法得到的水平放置的直观图中,求线段
的长.
(2)若一只蚂蚁沿漏斗表面从点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7c314398e26ffc7164b82946eeb4273.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
(3)将图中正方形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdcfe69b939fd1c271747fe9d37ccdf9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e663220a66eff19da6a71e46b397db2e.png)
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5 . 如图所示,某海域在A,B两处分别设有停靠码头,B在A北偏东30°相距
海里处,现由甲,乙两艘货船分别从A,B两处向C处航行.甲货船从A处以
海里/小时的速度沿着正东方向行驶,乙货船从B处以3海里/小时的速度向沿东偏南45°的方向行驶,当航行至1小时,甲货船到达E处,乙货船到达F处,此时乙货船因故障停止航行并发出求救信号,甲接到信号后立即掉转方向并以
海里/小时的速度行至F处施展抢修工作.
(2)若抢修工作共经历1小时,抢修结束后乙船仍以原速度驶向C处,则自乙船从B处出发到乙船行至C处为止,共经过了多长时间,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6214381b57afa4c26e6074251279294f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95bacae35b6e16a0a33c2bdc6bc07df7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38387ba1cadfd3dfc4dea4ca9f613cea.png)
(2)若抢修工作共经历1小时,抢修结束后乙船仍以原速度驶向C处,则自乙船从B处出发到乙船行至C处为止,共经过了多长时间,
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解题方法
6 . 如图1,等腰
满足
,
,
于
.如图2,将
绕着直线SA旋转时,在BA旋转而成的平面
内总有点
满足
,
,(点
,点
分别在直线BD两侧).
长;
(2)求证:
平面
;
(3)记三棱锥
的体积为
,三棱锥
的体积为
,当四棱锥
的体积最大时,求
值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79482c6de6bbd05affc78f9c625e52f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2affc8264f2e40743bb12dd7ea57177b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fe85217cea14241255ec21200b25b16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fe0bb7d51e559e73aa16a954fe7fa33.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79482c6de6bbd05affc78f9c625e52f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd284f76d9f5769bc189508ce2572b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c279c8033acb94c3f91be2e05b0a6bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/833cfda415649b832cc136caed392753.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a6e2867f32d3f1c3cd36cd3a11a8580.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10c83f8945042b9c8fb2fbdac9308d62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(3)记三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d535bfd65eb04a29d64425d54b2acf86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4764374bd2fb78e59cd0b283637baeb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69dd9f16a5c7a66e62e52fd66f4449ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63055a5d6916f99d07fede49120753f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c773ac7c3a6575fb7d432c93fe5f2a32.png)
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7 . 下列说法正确的是( )
A.已知![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
B.在![]() ![]() ![]() ![]() ![]() |
C.已知在![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
D.在![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
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解题方法
8 . 在
中,
.
(1)求
;
(2)除上述条件外,
同时满足____________,求
的值;
请从①
,②
,③
中选择一个符合题意的条件,补充到上面问题中,并完成解答.
(3)求
面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7ae935f403bc9fca71a78ca3c616278.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(2)除上述条件外,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c32e2f2d7147cf1699fbfdef9cf4af74.png)
请从①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4376af85e07b29051a812ff3fcda61a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcdb7a488910743dc5c63afb394b87e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3816ae0180de16f3ef7b01ed2cf9efd4.png)
(3)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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解题方法
9 . 已知
,
,
分别是
的三个内角
,
,
的对边,其中正确的命题有( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
A.已知![]() ![]() ![]() ![]() |
B.若![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
C.若![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() |
D.已知![]() ![]() ![]() ![]() ![]() ![]() |
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解题方法
10 . 已知函数
在
上单调递减,且在
中满足
,则下列情况中,能唯一确定该三角形形状的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68123dcb8d39b1a108d6c41c29e14083.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cd50020c0e3198d4a6b2d26a413b1b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e428e7a09732be85c1224e9c8f6a71c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfcc1eb1326895662d5b26a513bf4234.png)
A.角![]() | B.角![]() |
C.![]() | D.![]() |
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