document.write( "Question 257796: Find the area of the triangle ABC having vertices A(7,-4) B(3,1) C(-10,-8) \n" ); document.write( "
Algebra.Com's Answer #189680 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Find the area of the triangle ABC having vertices A(7,-4) B(3,1) C(-10,-8)\r\n" );
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document.write( "The area of a triangle with vertices (a,b), (c,d), and (e,f) is\r\n" );
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document.write( "\"Area=abs%28%281%2F2%29%2Aabs%28matrix%283%2C3%2Ca%2Cb%2C1%2Cc%2Cd%2C1%2Ce%2Cf%2C1%29%29%29\"\r\n" );
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document.write( "Do you know how to evaluate that determinant?  If not post again\r\n" );
document.write( "asking how.\r\n" );
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document.write( "\"Area=abs%28%281%2F2%29%2A%28101%29%29=abs%28101%29=101\"\r\n" );
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document.write( "Note that if you take the vertices in counter-clockwise order around\r\n" );
document.write( "the triangle, the absolute value bars are not necessary, because the\r\n" );
document.write( "area will come out positive anyway and so sometimes the formula is \r\n" );
document.write( "given without the absolute value bars, and they tell you to always\r\n" );
document.write( "take the vertices in counter-clockwise order; however if you include \r\n" );
document.write( "the absolute value bars, then it doesn't matter which order\r\n" );
document.write( "you take the vertices.  Notice that I took them counter-clock-wise above,\r\n" );
document.write( "and the absolute value bars were not really necessary.\r\n" );
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document.write( "Edwin
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