document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=180217>Question 180217</A>: <I><SPAN STYLE=\"word-break: break-all;\"> how do you prove that a parallelogram is a parallelogram </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #135073 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><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=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=135073\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font face=\"Times New Roman\" size=\"+2\">\r<BR>\n" );
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document.write( "You don't have to prove that a parallelogram is a parallelogram.  It just is.  I know that is sort of a smart-a** answer, but you have really asked the wrong question.  I'm reasonably certain that you want to know how to prove that a given quadrilateral is a parallelogram.\r<BR>\n" );
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document.write( "Going on that assumption, let's look at the definition of a parallelogram:\r<BR>\n" );
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document.write( "In geometry, a parallelogram is a quadrilateral with two sets of parallel sides. The opposite or facing sides of a parallelogram are of equal length, and the opposite angles of a parallelogram are of equal size.\r<BR>\n" );
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document.write( "So, you need to prove one of the following:\r<BR>\n" );
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document.write( "1.  Each set of opposite sides are parallel\r<BR>\n" );
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document.write( "2.  Each set of opposite sides are of equal length\r<BR>\n" );
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document.write( "3.  Each set of opposite angles are of equal measure\r<BR>\n" );
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document.write( "Not knowing anything more than you told me about the characteristics of the quadrilateral in question, I can't tell you much more than this.\r<BR>\n" );
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document.write( "John<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE e^{i\pi} + 1 = 0\"><BR>\n" );
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