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cindyqtran
- Junior | Next Rank: 30 Posts
- Posts: 21
- Joined: Sun Aug 26, 2007 11:45 am
If we join the ends of the enterence with center of circle we would get a 45-45-90 triangle with the angle at center = 90 degs
(coz 3/4 th of a circle 3/4*360)
hence sides are in ratio 1:1:sqrt(2)
if r is the radius of the circle, then we have
r*sqrt(2) =12 r =6*sqrt(2)
so perimeter = 3/4 * 2*pi* 6*sqrt(2)
=9pi * sqrt(2)
ans should be C
