document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=846877>Question 846877</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help me with my project...<BR>\n" );
document.write( "A regular pentagon is inscribed in a circle of whose radius is 18 cm. Find the perimeter of the pentagon...THANKS...I NEED IT NOW...THANK YOU SO SO SO SO MUCH </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #510007 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=510007\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Please help me with my project...<BR>\n" );
document.write( "A regular pentagon is inscribed in a circle of whose radius is 18 cm. Find the perimeter of the pentagon...<BR>\n" );
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document.write( "Sketch the figure and draw the 5 triangles formed by the sides and<BR>\n" );
document.write( "radii.<BR>\n" );
document.write( "The central angle of each triangle is 360/5 = 72 degrees<BR>\n" );
document.write( "The base angles are each (180-72)/2 = 108/2 = 54 degrees<BR>\n" );
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document.write( "Draw a perpendicular bisector to the base of one of the<BR>\n" );
document.write( "triangles; thus forming 2 right triangles.<BR>\n" );
document.write( "For one of those two triangles determine the base.<BR>\n" );
document.write( "hypotenuse = 18 cm<BR>\n" );
document.write( "base angle = 54 degrees<BR>\n" );
document.write( "cos(54 deg) = base/18<BR>\n" );
document.write( "base = 18*cos(54) = 10.58 cm<BR>\n" );
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document.write( "whole side of one side of the pentagon = 2*10.58 = 21.16 cm<BR>\n" );
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document.write( "Perimeter of the pentagon = 5*21.16 = 105.8 cm<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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document.write( " </SPAN>\n" );
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