document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=111468>Question 111468</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Given:   In triangle ABC, angle B = 120<BR>\n" );
document.write( "Proven:  angel A (equal sign with a line through it) 60 degrees <BR>\n" );
document.write( "Plan:    Use an indirect poof.<BR>\n" );
document.write( "(write the proof using the paragraph method) I am totally lost here, could someone help me? That’s my problem with algebra; it all looks like Chinese to me. lol<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #81283 by </B><A HREF=/tutors/aboutme.mpl?userid=MathLover1><B>MathLover1(20850)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathLover1><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=MathLover1><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=81283\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> \r<BR>\n" );
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document.write( "Given:   In triangle ABC, angle <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=B+=+120%5E+o ALIGN=MIDDLE  ALT=\"B+=+120%5E+o\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Proven:  angel A <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A ALIGN=MIDDLE  ALT=\"A\"   DISABLED_style= \"max-width:90%; height:auto;\" > is not equal to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=60%5E+o ALIGN=MIDDLE  ALT=\"60%5E+o\"   DISABLED_style= \"max-width:90%; height:auto;\" >  \r<BR>\n" );
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document.write( "If you use an indirect proof, you need to assume what you need <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=to ALIGN=MIDDLE  ALT=\"to\"   DISABLED_style= \"max-width:90%; height:auto;\" ><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+prove ALIGN=MIDDLE  ALT=\"+prove\"   DISABLED_style= \"max-width:90%; height:auto;\" ><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+is ALIGN=MIDDLE  ALT=\"+is\"   DISABLED_style= \"max-width:90%; height:auto;\" ><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+false ALIGN=MIDDLE  ALT=\"+false\"   DISABLED_style= \"max-width:90%; height:auto;\" >, and then show that something contradictory (absurd) happens.\r<BR>\n" );
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document.write( "You will need following steps:\r<BR>\n" );
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document.write( "Assume that the <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=opposite ALIGN=MIDDLE  ALT=\"opposite\"   DISABLED_style= \"max-width:90%; height:auto;\" > of what you are trying to prove is true; in \r<BR>\n" );
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document.write( "other words, assume that angle is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A=60%5E+o ALIGN=MIDDLE  ALT=\"A=60%5E+o\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "as we know, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=the ALIGN=MIDDLE  ALT=\"the\"   DISABLED_style= \"max-width:90%; height:auto;\" ><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+sum ALIGN=MIDDLE  ALT=\"+sum\"   DISABLED_style= \"max-width:90%; height:auto;\" ><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+of ALIGN=MIDDLE  ALT=\"+of\"   DISABLED_style= \"max-width:90%; height:auto;\" ><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+all ALIGN=MIDDLE  ALT=\"+all\"   DISABLED_style= \"max-width:90%; height:auto;\" ><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+three ALIGN=MIDDLE  ALT=\"+three\"   DISABLED_style= \"max-width:90%; height:auto;\" ><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+angles ALIGN=MIDDLE  ALT=\"+angles\"   DISABLED_style= \"max-width:90%; height:auto;\" > of <BR>\n" );
document.write( "a triangle is equal to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=180%5E+o+ ALIGN=MIDDLE  ALT=\"180%5E+o+\"   DISABLED_style= \"max-width:90%; height:auto;\" >degrees.\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A+%2B+B+%2B+C+=+180%5E+o ALIGN=MIDDLE  ALT=\"A+%2B+B+%2B+C+=+180%5E+o\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "you can solve for <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=C ALIGN=MIDDLE  ALT=\"C\"   DISABLED_style= \"max-width:90%; height:auto;\" > \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+C+=+180%5E+o+-+%28A+%2B+B%29 ALIGN=MIDDLE  ALT=\"+C+=+180%5E+o+-+%28A+%2B+B%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+C+=+180%5E+o+-+%2860%5E+o%2B+120%5E+o%29 ALIGN=MIDDLE  ALT=\"+C+=+180%5E+o+-+%2860%5E+o%2B+120%5E+o%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+C+=+180%5E+o+-++180%5E+o ALIGN=MIDDLE  ALT=\"+C+=+180%5E+o+-++180%5E+o\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+C+=+0+ ALIGN=MIDDLE  ALT=\"+C+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" >.....it is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=absurd ALIGN=MIDDLE  ALT=\"absurd\"   DISABLED_style= \"max-width:90%; height:auto;\" > to have one of three angles in a <BR>\n" );
document.write( "triangle equal to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0 ALIGN=MIDDLE  ALT=\"0\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So, you can conclude that, as it was proven, angel <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A ALIGN=MIDDLE  ALT=\"A\"   DISABLED_style= \"max-width:90%; height:auto;\" > is not equal to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=60%5E+o ALIGN=MIDDLE  ALT=\"60%5E+o\"   DISABLED_style= \"max-width:90%; height:auto;\" > <BR>\n" );
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