document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=58585>Question 58585</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 146. Height of a post. Betty observed that the lamppost in the front of her house cases a show of length 8 feet when the angle of inclination of the sun is 60 degrees.  How tall is the lamppost? (In a 30-60-90 right triangle, the side opposite 30 is one-half the length of the hypotenuse)\r<BR>\n" );
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document.write( "not sure how to solve  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #40135 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=40135\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Betty observed that the lamppost in the front of her house cases a shadow of length 8 feet when the angle of inclination of the sun is 60 degrees. How tall is the lamppost? (In a 30-60-90 right triangle, the side opposite 30 is one-half the length of the hypotenuse) <BR>\n" );
document.write( "not sure how to solve <BR>\n" );
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document.write( "Draw the picture.<BR>\n" );
document.write( "You should see a right triangle with the right<BR>\n" );
document.write( "angle at the base of the pole and the 60 degree<BR>\n" );
document.write( "angle opposite the pole at ground-level.<BR>\n" );
document.write( "The distance from the vertex of the 60 degree<BR>\n" );
document.write( "angle to the base of the pole is the shadow<BR>\n" );
document.write( "which is 8 ft long.<BR>\n" );
document.write( "The angle at the top of the pole is 30 degrees<BR>\n" );
document.write( "and the shadow is the side opposite the 30 degree<BR>\n" );
document.write( "angle.<BR>\n" );
document.write( "So, sine the side opposite the 30 degree angle<BR>\n" );
document.write( "is one-half the hypotenuse, the hypotenuse must<BR>\n" );
document.write( "be 16 ft.<BR>\n" );
document.write( "Now, using Pythagoras: hypotenuse^2 = 8^2 + pole^2<BR>\n" );
document.write( "16^2 = 8^2 + pole^2<BR>\n" );
document.write( "256 = 64 + pole^2<BR>\n" );
document.write( "pole^2 = 192<BR>\n" );
document.write( "pole^2 = 64*3<BR>\n" );
document.write( "pole = 8sqrt(3)<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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