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A and B are centers of two circles that touch each other ext
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03 Oct 2018, 06:57
03 Oct 2018, 06:57
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Expert Reply
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Question Stats:
87% (00:45) correct
12% (00:19) wrong based on 32 sessions
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A and B are centers of two circles that touch each other externally, as shown in the figure. What is the area of the circle whose diameter is AB ?
(A) \(4\pi\)
(B) \(\frac{25\pi}{4}\)
(C) \(9\pi\)
(D) \(16\pi\)
(E) \(25\pi\)
Re: A and B are centers of two circles that touch each other ext
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12 Feb 2019, 21:33
12 Feb 2019, 21:33
1
Expert Reply
The line segment AB = 5
the area of the circle with AB as its diameter means that the area of a circle with a diameter of 5.
the area of a circle is Pi*radius^2, or pi*r^2
the radius is half the diameter, so then r = 5/2
then the area is
Pi*(5/2)^2= Pi*25/4
The answer is B
the area of the circle with AB as its diameter means that the area of a circle with a diameter of 5.
the area of a circle is Pi*radius^2, or pi*r^2
the radius is half the diameter, so then r = 5/2
then the area is
Pi*(5/2)^2= Pi*25/4
The answer is B
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A and B are centers of two circles that touch each other ext
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06 Jun 2021, 08:48
06 Jun 2021, 08:48
1
A and B are centers of two circles that touch each other externally => Length of AB = 2+3 = 5
Now AB is the diameter of the new circle => Radius = \(\frac{1}{2}\) * AB = \(\frac{5}{2}\)
We know that Area of Circle = \(\pi\)\(r^2\) = \(\pi\)\((\frac{5}{2})^2\) = \(\pi\)\(\frac{25}{4}\) = \(\frac{25\pi}{4}\)
So, Answer will be B
Hope it helps!
Watch the following video to Learn Basics of Circles
Now AB is the diameter of the new circle => Radius = \(\frac{1}{2}\) * AB = \(\frac{5}{2}\)
We know that Area of Circle = \(\pi\)\(r^2\) = \(\pi\)\((\frac{5}{2})^2\) = \(\pi\)\(\frac{25}{4}\) = \(\frac{25\pi}{4}\)
So, Answer will be B
Hope it helps!
Watch the following video to Learn Basics of Circles
