How many triangles?

The Problem:

 Suppose that you have six rods, of length 1,2,3,4,5,6.  How many different triangles can you form from the rods? 

Extend the result to 7, 8, 9... and, if you can, to 2n (any even number) and 2n+1 (any odd number).



1.         When will a set of three rods not produce a triangle?

2.         Start by considering what triangles you can form when the longest rod is 4, then 5, 6...and so on.


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Last modified: June 18, 2007