document.write( "Question 1169194: Prove that if a, b, and c are the sides of a triangle, then so are sqrt(a), sqrt(b), and sqrt(c). What about a^2, b^2, and c^2? \n" ); document.write( "
Algebra.Com's Answer #793926 by ikleyn(52943)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "Prove that if a, b, and c are the sides of a triangle, then so are sqrt(a), sqrt(b), and sqrt(c).
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document.write( "Let assume that  \r\n" );
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document.write( "    \"sqrt%28a%29\" + \"sqrt%28b%29\" <= \"sqrt%28c%29\".    (1)\r\n" );
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document.write( "where \"a\", \"b\" and \"c\" are the sides of a triangle.\r\n" );
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document.write( "I want to lead it to CONTRADICTION.\r\n" );
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document.write( "Indeed, square both sides of (1). You will get\r\n" );
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document.write( "    a + \"2%2Asqrt%28ab%29\" + b <= c,   or\r\n" );
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document.write( "    a + b <= c - \"2%2Asqrt%28ab%29\".\r\n" );
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document.write( "Then even more so\r\n" );
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document.write( "    a + b < c.\r\n" );
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document.write( "But it contradicts to the triangle inequality  a + b > c.\r\n" );
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document.write( "Thus we proved that  a + b > c   IMPLIES   \"sqrt%28a%29\" + \"sqrt%28b%29\" > \"sqrt%28c%29\".\r\n" );
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document.write( "It works for any combinations of sides of a triangle.\r\n" );
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document.write( "Thus we proved that the values  \"sqrt%28a%29\",  \"sqrt%28b%29\",  \"sqrt%28c%29\" satisfy all triangle inequalities,\r\n" );
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document.write( "if  \"a\",  \"b\"  and  \"c\"  are the sides of a triangle.\r\n" );
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document.write( "It implies that if  \"a\",  \"b\"  and  \"c\"  are the sides of a triangle, then  \"sqrt%28a%29\",  \"sqrt%28b%29\",  and  \"sqrt%28c%29\"  form a triangle, too.\r\n" );
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