首页
登录
职称英语
In the figure above, x=2. What is the area of circle O?[img]2011q3/ct_egmatqj_eg
In the figure above, x=2. What is the area of circle O?[img]2011q3/ct_egmatqj_eg
游客
2025-02-27
33
管理
问题
In the figure above, x=2. What is the area of circle O?
选项
A、
B、
C、
D、
E、
答案
B
解析
Since we are looking for the area of the circle, we really need to find the radius. The line segment from the center of the circle to the vertex of the square is 2, so we can use that to find the radius. If you extend line x to the opposite vertex of the square, you have drawn a diagonal of that square, which is also the hypotenuse of a 45°-45°-90° triangle. The diagonal measures 4. You normally multiply a leg of a 45°-45°-90° triangle by
to get the hypotenuse, so we have to divide the hypotenuse by
to get the leg (which is also the side of the square and the diameter of the circle). Therefore, the diameter is equal to
and the radius is equal to
. But we’re not done; we still have to find the area. The formula for the area of a circle is A=nr2, so we have to substitute
in for r. Squaring both the top and bottom of the fraction, we get 4/2 , or 2. So the area of the circle is 2π.
转载请注明原文地址:https://tihaiku.com/zcyy/3975055.html
相关试题推荐
Intherectangularfigureabove,theareaoftheshadedregionisequaltothea
Whichofthefollowingcouldbetheequationoflinelinthefigureabove?[img]
Whatistheareaoftheshadedfigure?[img]2011q3/ct_egmatqj_egmatqchoose_0056_2
[img]2011q3/ct_egmatqm_egmatqchoose_0443_201121[/img]A、 B、 C、
[img]2011q3/ct_egmatqm_egmatqchoose_0195_20112[/img]A、18B、33C、36D、42E、45ET
[img]2011q3/ct_egmatqm_egmatqchoose_0182_201121[/img]A、[img]2011q3/ct_egmatqm_eg
IfZisrepresentedbythedecimal0.W7,whatisthedigitW?[img]2011q3/ct_egm
[img]2011q3/ct_egmatqm_egmatqchoose_0288_201121[/img]A、 B、 C、
Theequation[img]2011q3/ct_egmatqm_egmatqchoose_0283_201121[/img]relatesthev
[img]2011q3/ct_egmatqm_egmatqchoose_0280_20112[/img]Anewspaperpolled1,000
随机试题
HowtoReadEffectivelyManystudentstendtoreadb
Thecompanyhadabout20notebookcomput
为了便于涂抹,普通抹面砂浆要求比砌筑砂浆具有更好的()。A.和易性 B.流动
胸痹诊断
微生物限度检查中,控制菌培养温度为A.23~28℃B.25~28℃C.30~35
A. B. C. D.
下列与某食品厂相关的做法不符合食品安全法规定的是:A.该厂无需为食品安全风险评
首批申请试点的证券公司,最近一次证券公司分类评价为()。 A.A类B.
预埋件都应采取有效的防腐处理,当采用热镀锌防腐处理时,锌膜厚度应大于( )μm
在价值工程活动的方案创造阶段,为了激发出有价值的创新方案,会议主持人在开始时并不
最新回复
(
0
)