document.write( "Question 389081: given: A(2,3), B(5,-1), C(1,0), D(-4,-1), E(0,2), F(-1,-2)
\n" ); document.write( "prove: angle ABC is congruent to angle DEF
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Algebra.Com's Answer #275774 by richard1234(7193)\"\" \"About 
You can put this solution on YOUR website!
Instead of Pythagorean-theorem bashing, I'm only going to find the change in x and y for each pair of points:\r
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\n" ); document.write( "\n" ); document.write( "(The partial differential operator \"delta\" should be uppercase, which represents a total change. Also, I'm taking the absolute value since Pythagorean theorem only depends on the squares of the numbers, regardless of whether change is positive or negative.\r
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\n" ); document.write( "\n" ); document.write( "A,B
\n" ); document.write( "\"delta%28x%29+=+3\"
\n" ); document.write( "\"delta%28y%29+=+4\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "B,C
\n" ); document.write( "\"delta%28x%29+=+4\"
\n" ); document.write( "\"delta%28y%29+=+1\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "C,A
\n" ); document.write( "\"delta%28x%29+=+1\"
\n" ); document.write( "\"delta%28y%29+=+3\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "D,E
\n" ); document.write( "\"delta%28x%29+=+4\"
\n" ); document.write( "\"delta%28y%29+=+3\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "E,F
\n" ); document.write( "\"delta%28x%29+=+1\"
\n" ); document.write( "\"delta%28x%29+=+4\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "D,F
\n" ); document.write( "\"delta%28x%29+=+3\"
\n" ); document.write( "\"delta%28x%29+=+1\"\r
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\n" ); document.write( "\n" ); document.write( "We see that AB = DE = 5, AC = DF = \"sqrt%2810%29\", BC = EF = \"sqrt%2817%29\". By SSS, ABC and DEF are congruent triangles.
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