For this you will need four pennies. Arrange the pennies so that the centers of all four are equidistant from each other.

Example:

(1) (2) (3) (4)

This will not work because penny 1 and penny 4 are farther apart than penny 1 and penny 2.

three- is easy,  2r distance!

the fourth not in the same plane

Posted by Ady TZIDON on 2006-05-01 09:17:37