Placing Coins That TouchDate: 8/7/96 at 0:36:10 From: mzeman Subject: Placing Coins That Touch How many 20 cent coins can you put around a 20 cent coin with them all meeting together? Date: 9/1/96 at 17:31:57 From: Doctor Jerry Subject: Re: Placing Coins That Touch I assume you have tried an experiment and found that six coins can surround a coin of the same size. If you start with a circle of radius a and then draw two more circles, each of radius a and drawn so that they are externally tangent to each other and to the first circle, you will observe an equilateral triangle with vertices at the centers of the three circles. So, the central angle is 60 degrees. This process can be repeated around the first circle, so that six circles in all can be placed around the first circle. -Doctor Jerry, The Math Forum Check out our web site! http://mathforum.org/dr.math/ |
Search the Dr. Math Library: |
[Privacy Policy] [Terms of Use]
Ask Dr. Math^{TM}
© 1994-2015 The Math Forum
http://mathforum.org/dr.math/