document.write( "Question 1115402: If A (2,5), B(-3,10) and C (-5,2) are vertices of a triangle, find its area \n" ); document.write( "
Algebra.Com's Answer #730275 by MathLover1(20850)\"\" \"About 
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\n" ); document.write( "The area of a triangle with vertices (\"x%5B1%5D\",\"y%5B1%5D\"), (\"x%5B2%5D\",\"y%5B2%5D\"), (\"x%5B3%5D\",\"y%5B3%5D\") is:\r
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\n" ); document.write( "\n" ); document.write( "In this case, A (\"2\",\"5\")=(\"x%5B1%5D\",\"y%5B1%5D\"), B(\"-3\",\"10\")=(\"x%5B2%5D\",\"y%5B2%5D\") and C (\"-5\",\"2\")=(\"x%5B3%5D\",\"y%5B3%5D\"), we have\r
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\n" ); document.write( "\n" ); document.write( "\"A+=+%2820%2B15+-6+%2B50+-25+-+4%29+%2F+2\"\r
\n" ); document.write( "\n" ); document.write( "\"A+=+50+%2F+2\"\r
\n" ); document.write( "\n" ); document.write( "\"A+=+25\"\r
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\n" ); document.write( "\n" ); document.write( "A similar formula can be used to find the area of any polygon. \r
\n" ); document.write( "\n" ); document.write( " If you prefer not to use this formula, then another method is to use Distance Formula to find the length of each side:\r
\n" ); document.write( "\n" ); document.write( "side \"AB\", \"AC\", and \"BC\"
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\n" ); document.write( "A (\"2\",\"5\")
\n" ); document.write( "B(\"-3\",\"10\")
\n" ); document.write( "C (\"-5\",\"2\")\r
\n" ); document.write( "\n" ); document.write( "\"AB=%28x%5B1%5D-x%5B2%5D%29%5E2%2B%28y%5B1%5D-y%5B2%5D%29%5E2\" \r
\n" ); document.write( "\n" ); document.write( "\"AB=+sqrt%282-%28-3%29%29%5E2%2B%285-10%29%5E2%29\"
\n" ); document.write( "\"AB=+sqrt%282%2B3%29%5E2%2B%28-5%29%5E2%29\"
\n" ); document.write( " \"AB=sqrt%285%5E2%2B%28-5%29%5E2%29\"
\n" ); document.write( " \"AB=sqrt%2825%2B25%29\"
\n" ); document.write( "\"AB=sqrt%282%2A25%29\"
\n" ); document.write( "\"AB=5sqrt%282%29\"
\n" ); document.write( "\"AB=7.1+\" \r
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\n" ); document.write( "\n" ); document.write( "\"AC=%28x%5B1%5D-x%5B2%5D%29%5E2%2B%28y%5B1%5D-y%5B2%5D%29%5E2\" \r
\n" ); document.write( "\n" ); document.write( "\"AC=+sqrt%282-%28-5%29%29%5E2%2B%285-2%29%5E2%29\"
\n" ); document.write( "\"AC=+sqrt%282%2B5%29%5E2%2B3%5E2%29\"
\n" ); document.write( " \"AC=sqrt%287%5E2%2B3%5E2%29\"
\n" ); document.write( " \"AC=sqrt%2849%2B9%29\" \r
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\n" ); document.write( "\n" ); document.write( "\"AC=sqrt%2858%29\"
\n" ); document.write( "\"AC=7.6\" \r
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\n" ); document.write( "\n" ); document.write( " \"BC=%28x%5B1%5D-x%5B2%5D%29%5E2%2B%28y%5B1%5D-y%5B2%5D%29%5E2\"
\n" ); document.write( " \"BC=+sqrt%28-3-%28-5%29%29%5E2%2B%2810-2%29%5E2%29\"
\n" ); document.write( "\"BC=+sqrt%282%5E2%2B8%5E2%29\"
\n" ); document.write( "\"BC=+sqrt%2868%29\"
\n" ); document.write( "\"BC=+8.25\"\r
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\n" ); document.write( "\n" ); document.write( "since you have scalene triangle (no equal sides), you can also calculate the area from the lengths of all three sides using Heron's Formula\r
\n" ); document.write( "\n" ); document.write( "Calculate \"s\" (half of the triangles perimeter):\r
\n" ); document.write( "\n" ); document.write( "\"s+=+%28a%2Bb%2Bc%29%2F2\"
\n" ); document.write( "\"s+=+%287.1%2B7.6%2B8.25%29%2F2\"
\n" ); document.write( "\"s+=+11.475\"\r
\n" ); document.write( "\n" ); document.write( "Then calculate the Area:
\n" ); document.write( "\"A+=sqrt%28s%28s-AB%29%28s-AC%29%28s-BC%29%29\"
\n" ); document.write( "\"A+=sqrt%2811.475%2811.475-7.1%29%2811.475-7.6%29%2811.475-8.25%29%29\"
\n" ); document.write( "\"A+=25.0476\" round it to whole number
\n" ); document.write( "\"A+=25\"\r
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