Algebra.Com's Answer #82779 by Edwin McCravy(20055)![\"\"](\"/images/stars/stars-13.gif\")  
You can put this solution on YOUR website!
I do not have any clue what to do with this problem.
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document.write( "Solving oblique triangles using the law of cosines.
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document.write( "You have a triangle with 3 sides. It looks like this description: angle F is at the top, angle E is to the bottom right, and to the left of it is angle D.
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document.write( "between F and E it is 140. between E and D it is 156. between D and F is 96.
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document.write( "The question is: \"Find the size of angle F in oblique triangle DEF.
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document.write( "I hope this is descriptive enough for you to help me because I honestly have no clue what to do. I don't understand the law of cosines and the Law of Sines either.
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document.write( "The law of cosines for when you have all three sides and\r\n" );
document.write( "no angle given is\r\n" );
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document.write( " (one ADJACENT side)² + (other ADJACENT side)² - (OPPOSITE)²\r\n" );
document.write( "cosine(ANGLE) = -------------------------------------------------------------\r\n" );
document.write( " 2(one ADJACENT side)(other ADJACENT side)\r\n" );
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document.write( "The ANGLE we want to find is F.\r\n" );
document.write( "One ADJACENT side to F is DF which is 96 in length.\r\n" );
document.write( "The other ADJACENT side is EF which is 140 in length.\r\n" );
document.write( "The OPPOSITE side is the side across the triangle\r\n" );
document.write( "from angle F, which is DE, 156 in length.\r\n" );
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document.write( "Now we find the inverse cosine of that\r\n" );
document.write( "and we get \r\n" );
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document.write( "Angle F = 80.40594177°\r\n" );
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document.write( "Since the sides given are rounded to\r\n" );
document.write( "3 significant digits, we round the\r\n" );
document.write( "angle off to the nearest degree, so\r\n" );
document.write( "the answer is \r\n" );
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document.write( "Angle F = 80°\r\n" );
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document.write( "Edwin \r
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