document.write( "Question 1186350: Could you please help me write an INDIRECT PROOF for this problem?\r
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Algebra.Com's Answer #817315 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Assume BC is not congruent to DC.\r\n" );
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document.write( "1. AB ≅ AD        | given\r\n" );
document.write( "2. ∠BAC ≅ ∠DAC    | given\r\n" );
document.write( "3. AC ≅ AC        | reflexive property of equality\r\n" );
document.write( "4.  △BAC ≅ △DAC  | Side-angle-side  (SAS)\r\n" );
document.write( "5.  BC ≅ DC       | Corresponding parts of congruent triangles. (CPCT)  \r\n" );
document.write( "6.  BC ≅ DC       | 5 contradicts the assumption that BC is not congruent to DC.\r\n" );
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document.write( "Notice: the theorem was not proved at step 5, because 5 was deduced under the\r\n" );
document.write( "assumption BC is not congruent to DC.  The theorem was not proved there.  It was\r\n" );
document.write( "only proved by the statement 6 that the assumption leads to a contradiction.\r\n" );
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document.write( "Edwin
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