1 . 太原汾河四期工程北起尖草坪区上兰村汾河漫水桥(中北大学往南约
米),南至柴村桥北
米处.太原汾河四期的建成,成为市民节假日热门打卡之地.小明和小聪相约游览,他们利用无人机和所学的数学知识对某段河流的宽度
进行了测量.如图所示,小明站在河岸
处测得无人机
的仰角为
,小聪站在小明对面河岸
处测得无人机
的仰角为
,已知小明的身高
,小聪的身高
,无人机
距地面的高度为
(点
,
,
,
,
在同一个平面内).求河流的宽度
.(精确到
。参考数据:
,
,
)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/14/61a88d13-49b5-4622-8595-bf8951411775.png?resizew=261)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98ac61206cb12cf6686bb0facf635010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/821b8672d030c240ff230a0174aa7a3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1845ed03ec08feac9adee161aab3449.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ec692d0fed789a952522902815d541b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf2088d6fd1c5288253e927aa19b01d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a03a3794106382223ec07ffd8ab91a22.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)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfaa19eeaf415ed419e77fe92794f443.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52a49743c3433d9e3d95f5cc0bb87b0d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3935dc13ab225c9806bef648010c996.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75e9eaaeea5ab63e69cbc31e488d2cda.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/14/61a88d13-49b5-4622-8595-bf8951411775.png?resizew=261)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/14/d70fbad8-5297-4628-9905-7e3a02534eb5.png?resizew=190)
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2 . 阅读与思考
下面是小亮同学的数学日记,请仔细阅读,并完成相应的任务.
今天我在一本课外读物上看到下面的材料,要想在穿衣镜(平面镜)中看到自己的全身像,穿衣镜的长度至少是身高的一半.我有如下思考:
如图1,已知人
竖直站立,穿衣镜
竖直放置,此时
,
为眼睛的位置,
是人
在穿衣镜中的像,
,
分别是过
,
的法线与
的交点.
∵
和
是法线,
∴
,
.
∴
.
∴
.
∴四边形
是矩形.
∴
.
根据平面镜成像原理可知
,
在
和
,
,
,
,
∴
.
∴
.
……
因此,要想在穿衣镜中看到自己的全身像,穿衣镜上端处和人眼与头项的中点处齐平,此时穿衣镜有最小长度,即身高的一半.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/15/2c8d7f07-b197-4413-afae-74b6317a5c15.png?resizew=358)
任务:
(1)从小亮的日记中还可以知道
,
,可以用数学知识______来解释.
A.图形的轴对称 B.图形的旋转 C.图形的位似
(2)请你补全小亮的思考过程.
(3)应用:如图2,现有一面平面镜
,竖直挂在墙上,某人
身高为
,他站在镜子前某处,眼睛
只能看到部分身长
,若他想看到自己的全身像,则将镜子下移的距离
至少为______
.
下面是小亮同学的数学日记,请仔细阅读,并完成相应的任务.
×年×月×日 星期六 晴
利用教学知识求穿衣镜的最小长度
今天我在一本课外读物上看到下面的材料,要想在穿衣镜(平面镜)中看到自己的全身像,穿衣镜的长度至少是身高的一半.我有如下思考:
如图1,已知人
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2952c1bb3373bd9cb2b8c59c8ec55f4b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24cfad1ba71a78d8f415335cde2f8c52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88e9f7d1272b7344346b58b660aa260a.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83b86d8caeb168a36f20a02ee02bb7d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d9ebf55cadec703db791e748c72ee03.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/203df70f9d60c3507c6cf95c0d2b9c1a.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0361154122d59eed34514e416d77f72.png)
∴四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cec780e86f57790cf88ec761e219bf5f.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b112af121e615cc6068fd29dc4344900.png)
根据平面镜成像原理可知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0836b01b2cdc1a7d082a8f94fc835129.png)
在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c2b58424e893df4e01c912f87e09095.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6074f4beb31fb393ae3978e0035ae16f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0b943b3518dfc2fc8c9afdd57c1f41e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6f1cfcf1a3c040d448bcd67399b4d81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0836b01b2cdc1a7d082a8f94fc835129.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd05e96e6868403b39d58d1c8023b0f8.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fc5f0e2cc2158bd508edd68e05a892b.png)
……
因此,要想在穿衣镜中看到自己的全身像,穿衣镜上端处和人眼与头项的中点处齐平,此时穿衣镜有最小长度,即身高的一半.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/15/2c8d7f07-b197-4413-afae-74b6317a5c15.png?resizew=358)
任务:
(1)从小亮的日记中还可以知道
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942bc92f564e1466854527cc335ae6f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa7bd0f912d7e2e993b83f4f9a73708d.png)
A.图形的轴对称 B.图形的旋转 C.图形的位似
(2)请你补全小亮的思考过程.
(3)应用:如图2,现有一面平面镜
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a5f1641947153c80b987320885a2b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4851b4ac5eb7be62c282d97585714974.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60f32ebeea5cd332f252fffca82d047d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db8305c4ffbf876642440c3d28e91e9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efa9fbcfb9595e2f031aa691db4564b.png)
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3 . 如图,正方形
中,点
为对角线
上的一点,
,
,垂足分别为
,
,已知
,
,求
的长度.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b6cc3789c0e9b7d1226aa0de3327599.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/082292e52d5b734762cf9c139ee550bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/929adbe2211b012b66fe725d478274c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aeedb5f361a1baff6338436fff6c471d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/5/034c6bc0-9aa6-41c8-804f-6b5c027a08a7.png?resizew=170)
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名校
4 . 综合与实践
问题情境:
已知正方形
,点
是
边上一点,将正方形
绕点
顺时针旋转,得到正方形
,连接
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/8/9088a0a6-0cbb-4a43-b595-697060f8485b.png?resizew=423)
猜想证明:
(1)当
时,如图(1),
①连接
,
,
,求证:四边形
是矩形;
②试猜想线段
,
之间的数量关系,并说明理由.
解决问题:
(2)当
时,
①
______________(用含
的式子表示);
②当
,且点
在
的延长线上时,如图(2),若
,求
的长.
问题情境:
已知正方形
![](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/0dc5c9827dfd0be5a9c85962d6ccbfb1.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/0d609847e2ff3d64e5a514582c3ead0e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6024fd4532f5f981deac4582c799a6ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6655cc150ddc9deba2254780984d0024.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/8/9088a0a6-0cbb-4a43-b595-697060f8485b.png?resizew=423)
猜想证明:
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49c8dbc31b2e14067ef2f34b4e25f114.png)
①连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ffb952f86442845da723fd291564484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20ecac2dad4cffdd971fd23deacff3fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e0f0ccc8492a0ccf1eee24867060643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2131c5ec585f0cb29c28613011459d8e.png)
②试猜想线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6024fd4532f5f981deac4582c799a6ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6655cc150ddc9deba2254780984d0024.png)
解决问题:
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c432964f92f710068727d715a7307613.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6969c2f53a3e3a4293e36a824b5c7574.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
②当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be604061cf1591f7069472269d4c9719.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7c314398e26ffc7164b82946eeb4273.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6655cc150ddc9deba2254780984d0024.png)
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名校
5 . 元宵佳节灯火会上,有一名摄影爱好者为了记录这次灯火会的全过程,携带无人机进行航拍.如图,摄影爱好者在水平地面上点
处测得无人机位置点
的仰角为
.无人机从点
处水平飞到点
处,
米,摄影爱好者在点
处测得点
的仰角为
.已知
为水平地面,
,(即:点
,
,
,
四点在同一平面内),求无人机距离水平地面的高度.(测角仪的高度忽略不计,参考数据:
,
,
)
![](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/903c1bb6f9fe8f9b9710683a3e601452.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65a3e478bb87d094e3a0af30dd10ae8.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/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/880efdb2b4ac4861ad808e0162d082be.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)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d2082b0e4e457c2ea1e033d69d8b39d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92b15906c24c41d13588f3c4b5e19086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7664a5f9b61fd010eda340986ca34b47.png)
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2023-03-09更新
|
140次组卷
|
3卷引用:山西省大同市第一中学校2022-2023学年九年级下学期3月月考数学试题
山西省大同市第一中学校2022-2023学年九年级下学期3月月考数学试题(已下线)2023年新疆维吾尔族自治区中考数学真题变式题20-23题广东省云浮市罗定市2023-2024学年九年级下学期期中数学试题
6 . 如图,已知
的直径
,弦
,
的平分线交
于点
,过点
作
交
的延长线于点
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/25/4ecd4faa-5bb4-4448-9f04-bf81b6f9da1a.png?resizew=116)
(1)求证:
是
的切线.
(2)求
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc34db5860990e51ba31edc8cdd077c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4494a85de0be0b97a69348115aef8513.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68fbbd17c89f03dbb61cd6ffdb9a0344.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/25/4ecd4faa-5bb4-4448-9f04-bf81b6f9da1a.png?resizew=116)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d97cdc586744d208b6f69c9813af977.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
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7 . 综合与实践.
(1)问题1:如图①,以
为基础,借助无刻度直尺和圆规作一个平行四边形,标注字母,并说明理由;
(2)问题2:如图②,在平行四边形
中,对角线
,
相交于点O,取
的中点E,连接
并延长至点F,使得
,连接
,
,出现了新的特殊四边形,请判断其中一个四边形的形状,并说明理由;
(3)问题3:如图③,在问题2的平行四边形
中添加一个条件,使四边形
变成矩形,你添加的条件是 ,说明理由;
(4)问题4:如图④,在平行四边形
中,若
,过点O作直线
,如果
,
,试求出线段
的长度.(提示:利用勾股定理和菱形面积公式)
(1)问题1:如图①,以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3818a2c9919d358b4c3713396093822b.png)
(2)问题2:如图②,在平行四边形
![](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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a299d2b999568e80be8005565ba209a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/548c632acc0f0f2ae41f90ce24e23e59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
(3)问题3:如图③,在问题2的平行四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df1e902581960c17ad97a5e29e2c0c56.png)
(4)问题4:如图④,在平行四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7de966c316db1013defc56372fcf814e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66fae8e33cd86fa8dab72704eaafe1ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/305a88d4e0249bd16d48eda01331d2d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07140f277a35733d8c97577ccdd4e3ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/8/fa32bd55-f2b8-4d93-b768-a3744a7f4547.png?resizew=617)
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名校
8 . 如图,某无人机爱好者在一小区外放飞无人机,当无人机飞行到一定高度D点处时,无人机测得操控者A的俯角为
,测得小区楼房
顶端点C处的俯角为
.已知操控者A和小区楼房
之间的距离为45米,无人机的高度为
米.(假定点A,B,C,D都在同一平面内.参考数据:
,
.计算结果保留根号)
的高度;
(2)在(1)条件下,若无人机保持现有高度沿平行于
的方向,并以5米
秒的速度继续向右匀速飞行.问:经过多少秒时,无人机刚好离开了操控者的视线?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a4c9b697e3df2b5469b71d3b5e47a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b046923c56c5c3e238eb021925258c87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2edbeb61c165e3827556c2285e860ece.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f2a94aba7049c87952f6a599c4d8024.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
(2)在(1)条件下,若无人机保持现有高度沿平行于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4333bb203d02814c146ed587b69ea69d.png)
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2023-01-06更新
|
503次组卷
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8卷引用:山西省大同市第二中学校2022-2023学年九年级上学期期末数学试题
山西省大同市第二中学校2022-2023学年九年级上学期期末数学试题福建省泉州市惠安广海中学2022-2023学年九年级上学期期中考试数学试题(已下线)黄金卷01-【赢在中考·黄金8卷】备战2023年中考数学全真模拟卷(长沙专用)2023年广东省珠海市第八中学中考一模数学试卷(已下线)第03讲 三角函数的实际应用(知识解读+真题演练+课后巩固)-2023-2024学年九年级数学下册《知识解读·题型专练》(浙教版)(已下线)专题提升 解直角三角形的实际应用(30题)-【帮课堂】2023-2024学年九年级数学下册同步学与练(人教版)2024年河南省中考数学模拟试题2023年云南省初中学业水平模拟考试(新题型)数学模拟预测题
名校
9 . 如图,有一架秋千,当它静止在
的位置时,踏板离地的垂直高度为
,将秋千
往前推送
,到达
的位置,此时,秋千的踏板离地的垂直高度为
,秋千的绳索始终保持拉直的状态.
_______
,
_______
,
_______
;
(2)根据(1)中求得的数据,求秋千的长度.
(3)如果想要踏板离地的垂直高度为
时,需要将秋千
往前推送_______
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/122fc10d49eacb9aa36bff6d7f0652f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f36b51b654efcff60d2d640b9b4c4471.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db281746f70f790a129f2b896aae9f89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f79997547fb75e88ad1e2c66989a4a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e15e00f40396e914d1d9955bd7785f1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16ca90e8a784f990c4097eec9219908d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e15e00f40396e914d1d9955bd7785f1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1ec5d678ec42846e1d28301e3bfd4be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e15e00f40396e914d1d9955bd7785f1f.png)
(2)根据(1)中求得的数据,求秋千的长度.
(3)如果想要踏板离地的垂直高度为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7728c1b0692431c2ee9d4c08bbab5258.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e15e00f40396e914d1d9955bd7785f1f.png)
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2023-01-06更新
|
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14卷引用:山西省忻州地市2022-2023学年八年级下学期期中数学试题
山西省忻州地市2022-2023学年八年级下学期期中数学试题山西省忻州市 原平市南坡中学2022-2023学年八年级下学期期中数学试题辽宁省沈阳市浑南区2022-2023学年八年级上学期10月月考数学试题江苏省扬州市扬州中学教育集团树人学校2022-2023学年八年级上学期期末数学试题2023年湖北省武汉市江夏第一中学初中部八年级下学期3月月考数学试卷 江西省宜春市丰城中学2022-2023学年八年级下学期开学考试数学试卷 (已下线)第10讲 勾股定理逆定理及简单应用(3种题型)-【暑假自学课】2023年新八年级数学暑假精品课(苏科版)河南省信阳市平桥区2022-2023学年八年级下学期期末数学试题湖北省武汉华中师范大学第一附属美联实验学校2022-2023学年八年级下学期3月月考数学试题吉林省松原市宁江区宁江区第一中学2022-2023学年八年级下学期期中数学试题河北省保定区竞秀区2023-2024学年八年级上学期期中数学试题贵州省贵阳市多区联考2023-2024学年八年级上学期期中考试数学试题江苏省扬州市宝应县2022-2023学年八年级上学期期末模拟数学试题福建省莆田市涵江区青璜中学2023-2024学年八年级下学期月考数学试题
10 . 如图,某数学兴趣小组要测量学校旗杆的高度,在某一时刻测得
长的竹竿竖直放置时影长为
,在同时刻测量旗杆的影长时,因旗杆靠近一教学楼,影子不全落在地面上,有一部分落在墙上,测得落在地面上的影长为
,留在墙上的影高为
,求旗杆的高度.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2c6e4ecd4a91b0eb74f0d32e5da9b99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0b0a29de6469644aaec77fe701a2679.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d621fa409ef003869e4d9c49d5237728.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a7f5caacb86858c7b0f1ea1de7bd227.png)
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2022-12-12更新
|
135次组卷
|
7卷引用:山西省晋中市灵石县2023-2024学年九年级上学期月考数学试题
山西省晋中市灵石县2023-2024学年九年级上学期月考数学试题广东省揭阳市榕城区2021-2022学年九年级上学期期末考试数学试题(已下线)专题3.1 投影(专项训练)-2022-2023学年九年级数学下册《同步考点解读·专题训练》(浙教版)(已下线)第01讲 投影与视图(知识解读+真题演练+课后巩固)-2023-2024学年九年级数学上册《知识解读·题型专练》(北师大版)(已下线)专题18投影 (4个知识点3种题型1种中考考法)-【帮课堂】2023-2024学年九年级数学上册同步学与练(北师大版)(已下线)第01讲 投影与视图(知识解读+真题演练+课后巩固)-2023-2024学年九年级数学下册《知识解读·题型专练》(浙教版)(已下线)专题12用相似三角形解决问题(2个知识点4种题型2个中考考点)-【帮课堂】2023-2024学年九年级数学下册同步学与练(苏科版)