document.write( "Question 1140950: BD is the altitude of right triangle ABC. If AD=3 and DC=12, what is the length of BD?\r
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Algebra.Com's Answer #761494 by MathLover1(20849)\"\" \"About 
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\"BD\" is the altitude of right triangle \"ABC\". \r
\n" ); document.write( "\n" ); document.write( "If \"AD=3+\"and \"DC=12\", what is the length of \"BD\"?\r
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\n" ); document.write( "\n" ); document.write( "given: right triangle \"ABC\"=> angle \"B+=+90\"° and altitude divides angle \"B\" into two angles , < \"1\" and < \"2+\"\r
\n" ); document.write( "\n" ); document.write( "=> <\"1+%2B+2+=+90\"° ……(1)\r
\n" ); document.write( "\n" ); document.write( "\"BD\" is perpendicular to\"+AC+\"( given)\r
\n" ); document.write( "\n" ); document.write( "=> <\"1\" + < \"DCB+=+90\"° …….(2)\r
\n" ); document.write( "\n" ); document.write( "=> < \"DCB+\"= < \"2\" ………….by (1) & (2)\r
\n" ); document.write( "\n" ); document.write( "& < \"BAD\" = <\"1\"\r
\n" ); document.write( "\n" ); document.write( "So, triangle\"+BCD\" ~ triangle\"+ABD\" ( by AAA similarity theorem)\r
\n" ); document.write( "\n" ); document.write( "=> \"BC%2FAB+=+CD%2FBD+=+BD%2FAD\" ( corresponding sides of similar triangles)\r
\n" ); document.write( "\n" ); document.write( "=> \"BC%2FAB+=+12%2FBD+=+BD%2F3\"\r
\n" ); document.write( "\n" ); document.write( "= \"BD%5E2+=+36\"\r
\n" ); document.write( "\n" ); document.write( "=> \"BD+=+sqrt%2836%29\"\r
\n" ); document.write( "\n" ); document.write( "=> \"BD+=+6\"\r
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