Triangular Numbers Problem
In the Triangular Numbers Lesson and in Using Triangular Numbers we used dots arrayed in geometric shapes to find a formula for the sum of the 1st n Counting Numbers.
Use a similar strategy to find a formula for the sum of the first n odd numbers.
That is, use a pattern of geometric shapes to find the sum:
1 + 3 + 5 + 7 + ... + (2n - 1)
Note: the nth odd number is (2n - 1).
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email the author: Bruce Jacobs
Last modified: Thursday, February 6, 2003