document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=175611>Question 175611</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hi All,<BR>\n" );
document.write( "I'm a HS Senior with my last class in Geometry, I saw a problem similar to mine, but with a different fact to prove...so here it is:\r<BR>\n" );
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document.write( "Prove:If an isosceles triangle has an altitude fron the vertex to the base, then the altitude bisects the vertex angle\r<BR>\n" );
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document.write( "Given:(triangle)ABC is isosceles; (line) CD is the altitude to base (line) AB\r<BR>\n" );
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document.write( "To Prove: (line)CD bisects (angle) ACB\r<BR>\n" );
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document.write( "Plan: (this space is blank, what should I write here? It's slightly confusing)\r<BR>\n" );
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document.write( "What I do know now is that two sides are congruent, and the altitude creates two right angles. This is all pretty confusing to me, math isn't my strong suit. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #130729 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=130729\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> I'm assuming that the drawing looks something like this:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" src=\"http://i150.photobucket.com/albums/s91/jim_thompson5910/Algebra%20dot%20com/isoscelestriangle.png\" border=\"0\" alt=\"Photobucket\">\r<BR>\n" );
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document.write( "Here's a Two Column Proof:\r<BR>\n" );
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document.write( "<PRE STYLE=\"white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;\">\r\n" );
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document.write( "       Statement                                               Reason\r\n" );
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document.write( "1.     Triangle ABC is isosceles                               Given\r\n" );
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document.write( "2.     Angle DAC = Angle DBC                                   Definition of Isosceles\r\n" );
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document.write( "3.     Segment CD = Segment CD                                 Reflexive Property of Congruence\r\n" );
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document.write( "4.     Angle ADC is a right angle                              Definition of Altitude\r\n" );
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document.write( "5.     Angle BDC is a right angle                              Definition of Altitude\r\n" );
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document.write( "6.     Angle ADC = Angle BDC                                   All right angles are equal\r\n" );
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document.write( "7.     Triangle ACD = Triangle BCD                             AAS Property of Congruence\r\n" );
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document.write( "8.     Angle ACD = Angle BCD                                   CPCTC\r\n" );
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document.write( "9.     Segment CD bisects Angle BCD                            Definition of Bisected Angle\r\n" );
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document.write( "</PRE>       \r<BR>\n" );
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document.write( "Note: CPCTC = Corresponding Parts of Congruent Triangles are Congruent. \r<BR>\n" );
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document.write( "Remember, an isosceles triangle has two equal sides and two equal base angles. Also, keep in mind that a bisected angle (one that is cut in half) has two equal parts.\r<BR>\n" );
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document.write( "So the basic course of action is:\r<BR>\n" );
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document.write( "1) Prove that triangle ACD is congruent to triangle BCD\r<BR>\n" );
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document.write( "2) From there, you can show that the corresponding parts of the triangles are congruent (in this case the top angles)\r<BR>\n" );
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document.write( "3) Since they are congruent, this means that they form a larger angle that has been bisected (a bisected angle tells us that the angle forms two smaller equal parts)\r<BR>\n" );
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document.write( " </SPAN>\n" );
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