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Possible Duplicate:
calculate sides of the right triangle if I know 1 side and all the angles

I'm not sure how to do this with only 1 side given, but I have a right triangle with a 30 degree angle and an unmarked angle. One side is 4 and the other two are x any y.

How do I find the values of x and y?

I think the hypotenuse is x adjacent is y and 4 is opposite.

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    Since $sin(30^\circ)=\frac{1}{2}$, $cos(30^\circ)=\frac{\sqrt{3}}{2}$ and $\tan(30^\circ)=\sqrt{3}$, if for example the hypotenuse is the side given then you have that the side opposite (O) to the 30 degree angle is $\frac{O}{7}=sin(30^\circ)$ which gives you $O=7\cdot\frac{1}{2}$. If the side given is not the hypotenuse solve a similar equation accordingly2011-06-06

1 Answers 1

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Well, it's a right triangle. So one angle is 90, one is 30, and the other makes the sum be 180. So we know that angle.

Further, it matters which side is 7. Is it the hypotenuse? Is it a leg?

Finally, a right triangle with an angle of 30 has some very nice properties - it's well-studied, just like the 45-45-90 triangle. Do you know them?

I will not, unfortunately, tell you the answer as this is a homework question (but I appreciate you marking that - in the future, add other tags that mention what the question is actually about. I will edit your tags appropriately here).

Please comment on your work, and I'll guide you through the rest.

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    @Adam: not seeing the triangle, I can't confirm completely. But sin(30) = 0.5 is correct. And your solution for x, from what I can tell, is correct.2011-06-06