In a right triangle B = 55° 30', and b = 6.05. Find c and a.

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L3

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In a right triangle B = 55° 30', and b = 6.05. Find c and a.

Sighs. First off, whoever invented Trigonometry, was clearly not a very kind hearted person.

I am attempting to learn Trigonometry but things are not boding very well so far. It's Sines, that's getting me all mixed up. The site I'm using has the problem,

In a right triangle B = 55° 30', and b = 6.05. Find c and a.

Then it has under the answer,

c = b/sin B = 6.05/sin 55°30' = 7.34.
a = 4.16.

Now I see how since, sin B = b/c, c = b/sin B, which would equal 6.05/sin 55°30' , but I don't see how they get 7.34. I mean how do we know what the sin of 55°30' is, and therefore what to devide 6.05 by? What is it, I'm missing? I've gone through the lesson on the site several times, but see nothing that explains it (but I could very likely just be missing something).

I do understand however how they get a once they have the 7.34.
 
L3 said:
...how do we know what the sin of 55°30' is...?
Click to expand...
We set our calculators to "degree" mode, enter either "55 degrees, 30 minutes" or else "55 + 30/60 = 55 + 1/2 = 55.5 degrees", and punch the "SIN" button (or do the second and third steps in the reverse order, depending upon the calculator). :wink:
 
Re: In a right triangle B = 55° 30', and b = 6.05. Find c and a.

Heh, Lol! Yes, true. :) .

I guess I should rephrase the question. How would one go about doing it without a calculator? Or alternatively, what should I look for on Google, to learn how to do this?
 
If you're not allowed to use a calculator, you'll have to use a table of values. :shock:
 
Re: In a right triangle B = 55° 30', and b = 6.05. Find c and a.

Ah, okay, well then calculator it is then heh. Sorry. I always prefer to figure out how to do something first without a calculator. Didn’t realize this was one of those things you really do just need a calculator for.

Well thanks muchlies for the help! Back to the sines and cosines I go.
 
Re: In a right triangle B = 55° 30', and b = 6.05. Find c and a.

Another alternative. Use a slide rule.
 
Another alternative. Construct a sufficiently large and precise right triangle by carefully measuring one angle as 55 degrees 30 minutes. Measure the lengths of both the opposite side and the hypotenuse, with precision sufficient to meet your needs. Divide the former measurement by the latter.
 
mmm4444bot said:
...by carefully measuring one angle as 55 degrees 30 minutes.....
Click to expand...
Use a very finely tipped pen...not a felt pen...and make sure there's no crums on kitchen table...
 
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