题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023138-72365.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023138-58544.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023138-96245.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023138-72365.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023138-67352.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023139-75288.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023139-41328.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023139-25302.png)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023139-63760.png)
解析
试题分析:连接OB、OC,根据切线的性质可得∠ABO=90°,再由OB=2,
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023138-58544.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023139-75288.png)
连接OB、OC
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023140-12272.png)
∵
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023138-96245.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023138-72365.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023138-67352.png)
∴∠ABO=90°
∵OB=2,
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023138-58544.png)
∴∠BAO=30°
∴∠AOB=60°
∵
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023139-75288.png)
∴△OBC的面积等于△ABC的面积,∠OBC=60°
∵OB=OC
∴∠COB=60°
∴阴影部分的面积
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023140-24965.png)
点评:解题的关键是读懂题意及图形,正确作出辅助线,把阴影部分的面积转化为扇形的面积.
核心考点
举一反三
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023131-21108.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023131-14704.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023131-85216.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023131-21108.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023132-87569.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023132-87569.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023132-95649.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023132-86066.png)
求证:
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023132-95649.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023132-82665.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023133-24112.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023125-51834.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023125-51834.png)
A、相离 B、相切 C、相交 D、相切或相交
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023119-52396.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023120-66772.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023119-52396.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023120-66772.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023113-12906.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023113-86849.png)
(1)求∠F的正切值;
(2)联结DF,与半径OC交于H,求△FHO的面积。
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023109-17253.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023110-26646.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023110-26646.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023109-17253.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191105/20191105023110-45236.png)
最新试题
- 1在研究摩擦力特点的实验中,将木块放在水平长木板上,如图a所示,用力沿水平方向拉木块,拉力从0开始逐渐增大.分别用力传感器
- 2设F1和F2为双曲线的两个焦点, 若F1、F2、P(0,2b) 是正三角形的三个顶点, 则双曲线的离心率为[ ]
- 3如图是探究平面镜成像的实验装置,关于这个实验:①应选择______来研究平面镜成像特点(填“平面镜”或“平板玻璃”);②
- 42010年6月,A省B县第十五届人大常委会第二十一次会议以整改工作未达到预期效果为由否决了B县政府一项关于重大污染问题整
- 5As we all know , reading is to the mind______ food is to th
- 6-What are you doing for your vacation? -I _______my little s
- 7“当时所处的战争条件下,这种政策基本上是正确的。除了余粮收集制之外,当时我们是没有别的办法来实现粮食政策的。”列宁评价的
- 8John and I _____ friends for eight years. We first got to kn
- 9阅读示意图,并结合所学知识回答下列问题。(1)图片显示的主要是什么?你能用一句话来形容这一状况吗?___________
- 10等量异号点电荷线的中垂线上有a、b两点,如图所示,将一个带负电的电荷q从a沿此中垂线移到b,下列说法正确的是( )A.
热门考点
- 1如图是一个模拟膈肌的运动实验(1)该实验说明了肺泡在膈肌______(填“收缩”或“舒张”)时胀大,在膈肌______(
- 2一 When did the computer crash?一 This morning, while I the
- 3一游标卡尺的主尺最小分度1mm,游标上有10个小等分间隔,现用此卡尺来测量一工件的直径,如图所示,该工作的直径为____
- 4短文改错。 I watch TV until nearly 12 o"clock, so I could not
- 5以下关于惯性的说法正确的是( )A.高速运动的物体不容易停下来,所以物体运动速度越大,惯性越大B.用相同的水平力,分别
- 6解下列关于x方程.(1)12(x-1)=2-15(x+2)(2)x-30.5-x+40.25=6(3)mx+n=m(2x
- 7【题文】函数的定义域是( ).A.B.C.D.
- 8---Listen! Is Kitty in the next room? ---No, it ______ be K
- 9年近30岁的杨丽娟,16岁开始疯狂追星。其父母因劝阻无效,又溺爱女儿,不惜借债、买肾筹措旅费,以满足女儿到香港见偶像的要
- 10水管是圆柱形的物体,在施工中,常常如下图那样堆放,随着的增加,水管的总数是如何变化的?如果假设层数为n,物体总数为y,