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In the figure above, the circles centered at O1 and O2 have
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18 May 2020, 17:43
18 May 2020, 17:43
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#greprepclub In the figure above, the circles centered at.jpg [ 14.36 KiB | Viewed 3063 times ]
In the figure above, the circles centered at \(O_1\) and \(O_2\) have radii of equal length. If \(O_1O_2=9\) and AB=3, what is the circumference of the circle centered at \(O_1\) ?
A. 6π
B. 9π
C. 12π
D. 18π
E. 36π
Re: In the figure above, the circles centered at O1 and O2 have
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18 May 2020, 21:23
18 May 2020, 21:23
1
1
O1O2 - AB = O1A + BO2 = 9-3 = 6
Circles are of same radius, O1A = BO2 = 3
The radius of Circle: O1A + AB = 3+3 = 6
Circumference: 2π*radius = 2π*6 = 12π
Circles are of same radius, O1A = BO2 = 3
The radius of Circle: O1A + AB = 3+3 = 6
Circumference: 2π*radius = 2π*6 = 12π
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Re: In the figure above, the circles centered at O1 and O2 have
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19 May 2020, 05:49
19 May 2020, 05:49
3
Carcass wrote:
Attachment:
#greprepclub In the figure above, the circles centered at.jpg
In the figure above, the circles centered at \(O_1\) and \(O_2\) have radii of equal length. If \(O_1O_2=9\) and \(AB=3\), what is the circumference of the circle centered at \(O_1\) ?
A. 6π
B. 9π
C. 12π
D. 18π
E. 36π
Since the two circles are identical, the two lengths below (indicated by x) are the same length.
Let's also let y = the length of AB
Since we're told \(O_1O_2=9\), we can write: x + y + x = 9
Since we're told AB=3, we can write: x + 3 + x = 9
Solve to get x = 3
So the individual lengths are as follows:
This means we can calculate the radius of the circle centered at \(O_1\)
The radius = 3 + 3 = 6
Circumference of circle = 2πr = 2π(6) = 12π
Answer: C
Cheers,
Brent
