<PRE><B>Question 993872</B>
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A farmer has a triangular shaped field, FLD. DF-350m, FL= 240m and DL=400m. Calculate the angle to the nearest degree. 
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There are &amp;nbsp;3&amp;nbsp; angles. &amp;nbsp;Angle &amp;nbsp;F&amp;nbsp; is opposite the longest side.
Use the Cosine Law:
400^2 = 350^2 + 240^2 - 2*350*240*cos(F).


I got &amp;nbsp;m(&lt;I&gt;L&lt;/I&gt;&lt;B&gt;F&lt;/B&gt;) =~ 83° (approximately).


For the Cosine Law see, &amp;nbsp;for example, &amp;nbsp;the lesson &amp;nbsp;&lt;A HREF=http://www.algebra.com/algebra/homework/Trigonometry-basics/Proof-of-the-Law-of-Cosines-revisited.lesson&gt;Proof of the Law of Cosines revisited&lt;/A&gt;&amp;nbsp; in this site.


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