document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=761114>Question 761114</A>: <I><SPAN STYLE=\"word-break: break-all;\"> PLEASE HELP!I really don't understand how to do this.<BR>\n" );
document.write( "Complete the following proof.<BR>\n" );
document.write( "Prove: In an equilateral triangle the three medians are equal. \r<BR>\n" );
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document.write( "https://media.glynlyon.com/g_geo_2012/9/q415a.gif \r<BR>\n" );
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document.write( "This is how the answer looks: \r<BR>\n" );
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document.write( "http://assets.openstudy.com/updates/attachments/51ca4d0de4b063c0de5a6daf-leslie096-1372212537835-capture.png </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #463111 by </B><A HREF=/tutors/aboutme.mpl?userid=rothauserc><B>rothauserc(4718)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=rothauserc><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=rothauserc><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=463111\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Our equilateral triangle lives in the Cartesian coordinate system.  In this system, the distance between any two points is d = sqrt(( y2 - y1)^2 + (x2 - x1)^2 )<BR>\n" );
document.write( "so lets calculate the length of each median\r<BR>\n" );
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document.write( "QA = sqrt ( (b/2 - 0)^2 + (3a/2 - 0)^2 ) = sqrt( b^2/4 + 9a^2/4 ) = sqrt((9a^2+b^2)/4)=(1/2)sqrt(9a^2+b^2)<BR>\n" );
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document.write( "RB = sqrt ( (0 - b/2)^2 + (2a - a/2)^2 )<BR>\n" );
document.write( "RB = sqrt ( b^2/4 + (4a/2 - a/2)^2 )<BR>\n" );
document.write( "RB = sqrt ( b^2/4 + 9a^2/4)<BR>\n" );
document.write( "RB = (1/2)*sqrt(9a^2+b^2)<BR>\n" );
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document.write( "PC = sqrt ( (b-0)^2 + (a - a)^2 ) = sqrt (b^2) = b<BR>\n" );
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document.write( "now each side is 2a so the altitude b is equal to<BR>\n" );
document.write( "b = sqrt ( (2a)^2 - a^2 ) = sqrt (3a^2) = a*sqrt(3)<BR>\n" );
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document.write( "note that PC is a median and it is equal to b = a*sqrt(3)<BR>\n" );
document.write( "which means that QA and RB are also equal to a*sqrt(3)<BR>\n" );
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