document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=151992>Question 151992</A>: <I><SPAN STYLE=\"word-break: break-all;\"> How can you determine if two lines of perpendicular?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #111725 by </B><A HREF=/tutors/aboutme.mpl?userid=Earlsdon><B>Earlsdon(6294)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Earlsdon><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=111725\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You compare their slopes.<BR>\n" );
document.write( "If their slopes are equal, then the lines are parallel.<BR>\n" );
document.write( "If their slopes are negative reciprocals (like 3 and -1/3), then the lines are perpendicular.<BR>\n" );
document.write( "If their slopes are neither or the above, then the lines are neither parallel nor perpendicular, which means that the lines must intersect, if they are co-planar (lying in the same plane). </SPAN>\n" );
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