document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=163332>Question 163332</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I need a two-column proof for the following:\r<BR>\n" );
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document.write( "PROVE:If a diagonal of a parallelogram bisects an angle of the parallelogram, the parallelogram is a rhombus. (State your plan and give a proof.)\r<BR>\n" );
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document.write( "GIVEN:ABCD is a parallelogram with angle 1 congruent to angle 2.<BR>\n" );
document.write( "TO PROVE: ABCD is a rhombus.<BR>\n" );
document.write( "PLAN: ??????\r<BR>\n" );
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document.write( "Thanks in advance...Joanne </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #120392 by </B><A HREF=/tutors/aboutme.mpl?userid=elima><B>elima(1433)</B></A><img src=\"/images/stars/stars-12.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=elima><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=120392\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> It is hard to prove without seeing the figure to know where the angles are, but I'll give it a try;<BR>\n" );
document.write( "I am assuming <1 and <2 are opposite angles, if they are;<BR>\n" );
document.write( "Theorem:<BR>\n" );
document.write( "A parallelogram is a rhombus if and only if each diagonal bisects a pair of opposite angles.<BR>\n" );
document.write( "Plan: You can use SAS or SSS to find congruent triangles.Then use the congruent parts to help you prove the theorem.<BR>\n" );
document.write( "I hope this helps<BR>\n" );
document.write( ":) </SPAN>\n" );
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