document.write( "Question 448086: Could you please help me solve this problem?\r
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document.write( "Prove the Median Inequality: If M is the midpoint of side BC of triangle ABC, then AM is less than 1/2(AB+AC).\r
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document.write( "Thank you. \n" );
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Algebra.Com's Answer #308474 by richard1234(7193)![]() ![]() You can put this solution on YOUR website! Whoops, mixed up AM with BM. It occasionally happens when I try to solve a question without pen or paper. Anyway, I have come up with a new proof, which is similar to that of the other tutor's, but uses a different method of constructing it. Note that neither proof is necessarily more \"correct\" than the other.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Start with the original diagram (I have used the other tutor's as a reference):\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "We can extend CA past A, and draw a line through B parallel to AM, and call their intersection E:\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "By AAA similarity, we can show that triangles EBC and AMC are similar, with a ratio of 2:1 (since BC = CM). Hence, we can establish the following ratios:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "EB = 2AM \n" ); document.write( "AC = AE\r \n" ); document.write( "\n" ); document.write( "From the triangle inequality, EB < AB + AE. Since EB = 2AM and AC = AE, we obtain 2AM < AB + AC --> AM < (AB + AC)/2. \n" ); document.write( " |