# Help solving triangle please

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• May 19th 2013, 09:34 AM
matt4395
Help solving triangle please
Hey guys and girls I have a maths problem I'm stuck on I keep seeming to get the wrong answer when I move on to work out the angle of the triangle. Attached is the question and my working sheet in an image format. If anyone could tell me where I've gone wrong and help that would be great!

Thanks in advance.Attachment 28412
Attachment 28413Attachment 28413Like I said it is when using the cosine rule to work out the angle that I struggle and seem to get the wrong answer.
• May 19th 2013, 10:14 AM
Paze
Re: Help solving triangle please
Can you upload the picture to imgur or some place? I can barely read the text.
• May 19th 2013, 10:35 AM
matt4395
Re: Help solving triangle please
Here's the link to view the images: matt4935's uploaded images - Imgur
• May 19th 2013, 11:26 AM
Paze
Re: Help solving triangle please
Quote:

Originally Posted by matt4395
Here's the link to view the images: matt4935's uploaded images - Imgur

"matt4935's images are not publicly available."
• May 19th 2013, 12:24 PM
matt4395
Re: Help solving triangle please
Hey sorry about that new to using this website.

imgur: the simple image sharer
imgur: the simple image sharer

Hope this works!
• May 19th 2013, 02:30 PM
HallsofIvy
Re: Help solving triangle please
You have a triangle, ABD, in which the side AB has length 6m, side BD has length 5m and the angle ABD is 20 degrees. The "cosine law" say that AB has length s where $s^2= 6^2+ 5^2- 2(6)(5)cos(20)= 36+ 25- 10(0.93969)= 61- 9.4= 51.6$
• May 20th 2013, 08:19 PM
ibdutt
Re: Help solving triangle please
• May 21st 2013, 11:11 AM
matt4395
Re: Help solving triangle please
ah thank you very much I think I see where I have gone wrong now
• May 21st 2013, 12:00 PM
matt4395
Re: Help solving triangle please
Poo I meant it was when using the sine rule! Darn! SORRY Guys but yeah I actually did get the Cosine wrong