document.write( "Question 49791: Question:How can I write a formal proof of the theorem.\r
\n" ); document.write( "\n" ); document.write( "\"If the base angles of a triangle are congruent, then the triangle is isosceles\"\r
\n" ); document.write( "\n" ); document.write( "This was my proof that was incorrect.\r
\n" ); document.write( "\n" ); document.write( "Given: angle DAB=DAC (told not base angles)\r
\n" ); document.write( "\n" ); document.write( "STATEMENTS REASONS
\n" ); document.write( "1. angleDAB=angleDAC 1. Given
\n" ); document.write( "2. DA-DA 2. Reflexive Property
\n" ); document.write( "3. Triangle BAD=Triangle CAB 3. SSS
\n" ); document.write( "4. BD=ED 4. CPCTC
\n" ); document.write( "5. angleBAD=angle CAD 5. Converse Base Angle Theorem
\n" ); document.write( "6. AD bisect BC 6. Def. of an Isosceles Triangle
\n" ); document.write( "7. triangle ABD=Triangle ACD 7. Isosceles Triangle\r
\n" ); document.write( "\n" ); document.write( "Could you please show me the correct way to prove this theorem?
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Algebra.Com's Answer #33039 by AnlytcPhil(1806)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Question:How can I write a formal proof of the theorem.\r\n" );
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document.write( "\"If the base angles of a triangle are congruent, then \r\n" );
document.write( "the triangle is isosceles\"\r\n" );
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document.write( "Could you please show me the correct way to prove this \r\n" );
document.write( "theorem?\r\n" );
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document.write( "Given: DABC, ÐA @ ÐC \r\n" );
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document.write( "     B\r\n" );
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document.write( "   /   \\r\n" );
document.write( "  /     \\r\n" );
document.write( " /       \\r\n" );
document.write( "A¯¯¯¯¯¯¯¯¯C\r\n" );
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document.write( "Draw altitude BD \r\n" );
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document.write( "     B\r\n" );
document.write( "    /|\\r\n" );
document.write( "   / | \\r\n" );
document.write( "  /  |  \\r\n" );
document.write( " /   |   \\r\n" );
document.write( "A¯¯¯¯D¯¯¯¯C\r\n" );
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document.write( "STATEMENTS                       REASONS\r\n" );
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document.write( "1. ÐA @ ÐC                       1. Given\r\n" );
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document.write( "2. BD @ BD                       2. Reflexive Property\r\n" );
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document.write( "3. BD ^ AC                       3. Altitude is ^ the base it's\r\n" );
document.write( "                                    drawn to   \r\n" );
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document.write( "4. ÐADB @ ÐCDB = 90°             4. BD ^ AC \r\n" );
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document.write( "5. DBAD @ DBCD                   5. AAS\r\n" );
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document.write( "6. BA @ BC                       6. CPCTC\r\n" );
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document.write( "7. DABC is isoceles              7. It has two congruent sides  \r\n" );
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document.write( "Edwin
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