document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1150867>Question 1150867</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An object that repeats itself every 120 degrees of rotation has rotation symmetry of order:  <BR>\n" );
document.write( "a) 0<BR>\n" );
document.write( "b) 1<BR>\n" );
document.write( "c) 3<BR>\n" );
document.write( "d) 4<BR>\n" );
document.write( "and why? </SPAN>\n" );
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document.write( "Answer: <font color=red size=4>C) 3</font>\r<BR>\n" );
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document.write( "This is because there are 360 degrees in a full circle, and 360/120 = 3. \r<BR>\n" );
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document.write( "Imagine an equilateral triangle that has one vertex pointing directly north. If we rotate that triangle 120 degrees (clockwise or counterclockwise, it doesnt matter), we get the same exact triangle as before: an equilateral triangle with one vertex pointing directly north. \r<BR>\n" );
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document.write( "It might help to cut out an equilateral triangle to place on your desk, then have a friend rotate the triangle as instructed. If you close your eyes during the rotation, then you'll open them to find that nothing has changed. The \"before\" and \"after\" triangles are identical. \r<BR>\n" );
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document.write( "This process happens exactly 3 times before the angle of rotation gets to 360 (after that point you've done a full revolution and back to square one). So that's one interpretation of what the \"3\" means. The link below probably does a much better job explaining through a visual approach.\r<BR>\n" );
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document.write( "More information<BR>\n" );
document.write( "<a  rel=nofollow HREF= \"https://www.mathsisfun.com/geometry/symmetry-rotational.html\">https://www.mathsisfun.com/geometry/symmetry-rotational.html</a><BR>\n" );
document.write( "The page shows various examples of rotational symmetry through really cool animations.<BR>\n" );
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