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
30
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
ItwasClark’sfirstvisittoLondonUndergroundRailway.Against【C1】______
Todaywehavea(an)tendencytolabelobesityasadisgrace.Theoverweighta
I’mgladthatyourstory______havewonthefirstprize.A、couldB、shouldC、migh
May,7,2009
AlthoughBeethovencouldsitdownandmakeupmusiceasily,hisreallygreat
下列关于操作风险的说法,错误的是( )。A.操作风险普遍存在于商业银行业务和管
量本利分析法是利用产值、成本、利润三者的关系预测()。A.计划成本的方法 B
有的老师怕影响总体成绩,不让成绩差的学生参加考试,侵犯了学生的() A.受教
通常情况下,()因素更值得投资者重视。A:资产重估与资产处置B:稳定持久的主营
适用于中压以下空调系统,但对相对湿度90%以上的系统不适用的是( )。A.酚醛复
最新回复
(
0
)