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Source: — Data Sufficiency |
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by clock60 » Sun May 15, 2011 3:14 am
hi i hope that the answer is D
second st is easier
(2)if x=60, then angle BCD=120, and angle CBD=30, thus triangle BCD is isosceles. and BC=6.
so suff
(1) with brute force, if you know 2 sides of triangle and angle between them. you can calculate the last side using cosine theorem, no need to calculate, but simply to know
BC^2=CD^2+BD^2-2*CD*BD*cos30, now know that BD=6*3^1/2, CD=6, and cos 30 is fixed value ((3^1/2)/2)
so you can find BC
also suff
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by abhi0697 » Sun May 15, 2011 9:34 pm
Agree with D
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by ankurmit » Mon May 16, 2011 7:10 am
clock60 wrote:hi i hope that the answer is D
second st is easier
(2)if x=60, then angle BCD=120, and angle CBD=30, thus triangle BCD is isosceles. and BC=6.
so suff
(1) with brute force, if you know 2 sides of triangle and angle between them. you can calculate the last side using cosine theorem, no need to calculate, but simply to know
BC^2=CD^2+BD^2-2*CD*BD*cos30, now know that BD=6*3^1/2, CD=6, and cos 30 is fixed value ((3^1/2)/2)
so you can find BC
also suff
thanks
--------
Ankur mittal
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