7-, 9-Sided PolygonsDate: 9/13/96 at 16:2:31 From: Dee Sypherd Subject: 7, 9 Sided Polygons Dear Dr. Math, What is the name of a 7-sided figure? What is the name of a 9-sided figure? Is one of these ever called a septagon? Thank you, Mrs. Sypherd's 4th - 6th grade class Ayr Public School Ayr, NE Date: 9/13/96 at 17:7:2 From: Doctor Tom Subject: Re: 7, 9 Sided Polygons The "official" names use Greek, not Latin prefixes, so they are heptagon and nonagon for 7- and 9-sided figures. There's a list of names of polygons in the Dr. Math FAQ. Look for "Naming polygons" at: http://mathforum.org/dr.math/faq/ -Doctor Tom, The Math Forum Check out our web site! http://mathforum.org/dr.math/ Date: 9/16/96 at 9:36:42 From: Dee Sypherd Subject: Re: 7, 9 Sided Polygons Dear Dr. Math, Thank you for your help with polygons. We have another question regarding the prefix "sept". If "septi" means seven, why is September the 9th month of the year? Thanks, Mrs. Sypherd's Class (4th - 6th Grades) Ayr Public School Ayr, NE Date: 9/16/96 at 14:6:4 From: Doctor Tom Subject: Re: 7, 9 Sided Polygons And "Oct"ober means 8 and "Nov"ember 9 and "Dec"ember 10. There used to be only 10 months, but 2 were added later. But rather than change the names, the two months were simply stuffed in. I've forgotten the exact history of this, but I remember reading a great description of this by Isaac Asimov in one of his books. The history of the calendar is fascinating. The main problem was a desire to synchronize "months" with the moon's motion, and that actually has little to do with the motion of the earth around the sun. -Doctor Tom, The Math Forum Check out our web site! http://mathforum.org/dr.math/ |
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