document.write( "Question 968332: A triangle is defined by the three points:\r
\n" ); document.write( "\n" ); document.write( "A=(5,2)\r
\n" ); document.write( "\n" ); document.write( "B=(7,5)\r
\n" ); document.write( "\n" ); document.write( "C=(8,4).\r
\n" ); document.write( "\n" ); document.write( "Determine all three angles in the triangle (in radians).\r
\n" ); document.write( "\n" ); document.write( "θa = \r
\n" ); document.write( "\n" ); document.write( "θb = \r
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Algebra.Com's Answer #591734 by Edwin McCravy(20055) $\"\"$ $\"About$

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A=(5,2)
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document.write( "This could be done with lengths of sides and the law of cosines but it\r\n" );
document.write( "is more easily done with angles between lines using slopes.\r\n" );
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document.write( "All three of those angles appear to be acute (less than 90°)\r\n" );
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document.write( "The acute angle between two lines is given by \r\n" );
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document.write( "∠A is the angle between AB and AC.\r\n" );
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document.write( "We find the slope of AB and call it m₁\r\n" );
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document.write( "We find the slope of AC and call it m₂\r\n" );
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document.write( "Substitute these in:\r\n" );
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document.write( "Multiply top and bottom by LCD of 6\r\n" );
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document.write( "Notice that instead of calling the angle ∠A, here \r\n" );
document.write( "it is called θ_A. \r\n" );
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document.write( "Find the other two angles the same way.\r\n" );
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document.write( "Edwin

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