One for trigonometry gurus here

Since there doesn't appear to be a correct answer so far:

c = (b*sin(C))/sin(B) = (784*sin(13))/sin(110) = 187.68 units

Edit: DAMMIT!
 
:D

DSC_0225_zps3dyrn2ko.jpg
 
Tuppy_Glossop said:
You need a right-angled triangle for sin, cos, and tan to work. Drop a line from point B that hits line AC at a right angle. You then have two right-angled triangles whose angles you know. Then set up some simultaneous equations for one of the triangles and solve them for the length of the common side (the one we made). Calc the rest from trig identities.
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That is how I would have done it. 33degree angle added to bring the 57 up to 90 and then you have a right angles triangle to work with. Sine cos tan the length of the new drop you created and you now have 2 angles and a side to work with. That gives you AB and then you are home free

Or you could go upwards with the 80 degree angle
 
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Gixer said:
My little excel trig file doesn't agree with anyone!

A-B 176.3616
B-C 763.90613

XRxGJ7i.jpg.png
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take a look at the triangle in the OP and the triangle in your excel sheet you're blindly applying - do they look a bit different to you

what is angle A in yours, what is angle B in the OP's?

edit - Also looks like you have manually entered both B and C in that sheet, should probably change the sheet to only allow you to enter one - you've currently given it a right angle triangle that doesn't exist
 
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Could be right there Dowie, I did notice that on one of the other lines when I put in the values I got differing results. Now I have to be careful when I use this tool myself :D bloody trigonometry!

So SINE is for a triangle with 90deg angle in it? Thanks for the explanation.
 
The only reason some of you need a 90 degree angle is because you have learnt incomplete trig rules.

If you know the sine and cosine rule, you do not need right angles! They are worth learning and really quite simple.

I'll post this again as it will teach you both. GCSE Maths.

http://www.bbc.co.uk/schools/gcsebitesize/maths/geometry/furthertrigonometryhirev1.shtml

The common soh, cah, toa rules drop out of these more complete rules where a 90 degree angle exists. Sine of 90 degrees is 1 and the Cosine of 90 is 0. So the Sine and Cosine rules are more general forms.
 
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