500 ps test23 #20

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500 ps test23 #20

by dunkin77 » Mon Apr 16, 2007 11:11 am
Hi,

Can anyone please help? thanks!



(the correct answer is C) )
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by Ramesh2007 » Mon Apr 16, 2007 6:35 pm
Draw two lines from center to the end of the base. Now these two line reprent the radius.

Now you have an isoceles triangle with hypoteneus as the base = 12 ft.

Since two other sides (radii) are equal, you get radius = 12/sqrt2.

Now calculate the circuference and multiply this will 3/4 which gives you 9 * pi * sqrt2.

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by RAGS » Tue Apr 17, 2007 6:46 am
ramesh u should say that the angle subtended at the center is 90 sinnce 1/4 *360=90 then go ahead to solve

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by dunkin77 » Tue Apr 17, 2007 7:32 am
Thanks both for your response.

Yes, that is a good point. I was at first wondering why we can determine the triangle 1:1:sqart2 but then I realize the it's 90degree triangle.

:)

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by ns88 » Tue Apr 17, 2007 9:14 am
Ramesh2007 wrote: Since two other sides (radii) are equal, you get radius = 12/sqrt2.

Now calculate the circuference and multiply this will 3/4 which gives you 9 * pi * sqrt2.
i think the radius is 6 * sqrt2

only then you get 9* pi * sqrt 2

no?