sine rule !

Problem Solving — algebra and arithmetic (GMAT Focus Edition)
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sine rule !

by marmar29 » Fri Apr 22, 2011 9:56 pm
wht is the sine of 45 if u knw tht the opposite side =1 n its right -angled traingle

a) 1
b)1/2
c)1/square root 2
d)square root 2

please show me how u reach the answer!
Source: — Quantitative Reasoning |

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by vineeshp » Sat Apr 23, 2011 1:32 am
Trigonometry is outside the scope of GMAT.
Vineesh,
Just telling you what I know and think. I am not the expert. :)

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by VivianKerr » Sat Apr 23, 2011 11:19 am
Vineeshp is correct. Luckily, you won't see any Trig on the GMAT.

This question is asking you about a 45-45-90 triangle. The ratio of the sides in a 45-45-90 is x: x: x*sq.rt of 2.

Image

The question says that n = 1, so the sides of this triangle will be 1, 1, and sq. root of 2.

Sine = Opposite/Hypotenuse

Sin 45 = 1 / sq. root of 2

Again, this is totally outside of the GMAT scope, but if you need to review more Trig, I recommend Purple Math's explanations: https://www.purplemath.com/modules/basirati.htm
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