document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=79709>Question 79709</A>: <I><SPAN STYLE=\"word-break: break-all;\"> REVIEW\r<BR>\n" );
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document.write( "30: The radius of a Circle O is 4, if radii OA and OB form 90o angle, AB = ? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #57210 by </B><A HREF=/tutors/aboutme.mpl?userid=doctor_who><B>doctor_who(15)</B></A><img src=\"/images/stars/stars-06.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=doctor_who><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=57210\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> There are 360o in a circle, so if the angle between OA and OB is 90o then you've cut a slice exactly equal to a quarter of a circle.  (because 360 = 90 X 4)\r<BR>\n" );
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document.write( "The formula for the whole circumference of the circle is pi X radius squared\r<BR>\n" );
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document.write( ".. which is pi X 4 X 4  =  16 X pi.\r<BR>\n" );
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document.write( "You've got exactly a quarter of that, so AB is 4 X pi.  (ANSWER)\r<BR>\n" );
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document.write( "If you need an exact answer, work it out on a clculator, knowing that pi = 3.14159  (approximately)<BR>\n" );
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