document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=969542>Question 969542</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A regular triangular pyramid with a slant height of 9m has a volume equal to 50m^3. find the lateral area of pyramid?\r<BR>\n" );
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document.write( "i really want to know how to solve this, please need help. i tried but i failed. and dunno where to put this topic, thanks </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #592408 by </B><A HREF=/tutors/aboutme.mpl?userid=rothauserc><B>rothauserc(4718)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=rothauserc><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=rothauserc><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=592408\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Lateral area = (1/2) * (perimeter of the base) * (slant height) <BR>\n" );
document.write( "A regular triangular pyramid is a regular tetrahedron which is made up of four equilateral triangles <BR>\n" );
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document.write( "The slant height is the height(h) of one of the equilateral triangles so by Pythagoras we have <BR>\n" );
document.write( "h^2 + (a^2/4) = a^2 where a is the length of a side<BR>\n" );
document.write( "9^2 + (a^2/4) = a^2<BR>\n" );
document.write( "3a^2/4 = 81<BR>\n" );
document.write( "3a^2 = 324<BR>\n" );
document.write( "a^2 = 108<BR>\n" );
document.write( "a = 10.392304845m approx 10.39m<BR>\n" );
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document.write( "perimeter of the base is 3 * (10.39) = 31.17<BR>\n" );
document.write( "lateral area = (1/2) * 31.17 * 9 = 140.265 approx 140.27m<BR>\n" );
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