document.write( "Question 474958: given: triangle ABC is isosceles, CD is the altitude to base AB
\n" ); document.write( "prove: CD bisects angle ACB\r
\n" ); document.write( "\n" ); document.write( "i think that we will use the Angle Side Angle postulate? \n" ); document.write( "
Algebra.Com's Answer #325694 by Edwin McCravy(20059)\"\" \"About 
You can put this solution on YOUR website!
\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Triangles ADC and BDC are right triangles (due to\r\n" );
document.write( "CD being an altitude)\r\n" );
document.write( "\r\n" );
document.write( "The two acute angles in a right triangle are complementary.\r\n" );
document.write( "\r\n" );
document.write( "Angles A and B are congruent because they are base angles\r\n" );
document.write( "of isosceles triangle ABC.\r\n" );
document.write( "\r\n" );
document.write( "Therefore angles ACD and BCD are congruent because\r\n" );
document.write( "they are complements of congruent angles A and B.\r\n" );
document.write( "\r\n" );
document.write( "Therefore, CD bisects angle ACB. \r\n" );
document.write( "\r\n" );
document.write( "You can write that up in a two column proof.\r\n" );
document.write( "\r\n" );
document.write( "Edwin

\n" ); document.write( " \n" ); document.write( "
\n" );