an orderly manner

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an orderly manner

by sanju09 » Sat Mar 06, 2010 3:10 am
Four circles, each of radii 7, are put in a way that a square of side 14 is formed if the centers are joined in an orderly manner. Another circle is made to pass through the four centers (name it circle I) and yet another circle is made to pass through the four points of contact (name it circle II). How much more is the area of circle I than that of the circle II? Take π = 22/7.
(A) 49
(B) 98
(C) 154
(D) 176
(E) 198
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by kstv » Sat Mar 06, 2010 4:12 am
IMO C

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by sanju09 » Sat Mar 06, 2010 4:25 am
kstv wrote:IMO C
How would it suffice to the members at large?
The mind is everything. What you think you become. -Lord Buddha



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by kstv » Sun Mar 07, 2010 4:08 am
Circle I radius = R , where 2R²= 14² . The side of the square is 14 and forms a 90 45 45 triangle with the two radius
Circle II radius r = 7 r²= 7² this is inscribed in the square.

Area of CI - CII = 22/7(14²/2 - 7²) = 154