Hello All, thank you for your help.

I am at a complete loss in this problem:

Attatched are the triangular numbers used to do the problem, and a table clarifying a few things.

The "n" row on the table states what n equals.

The "nth Triangular Number" row states how many dots there are when n=a certain number. (So when n=1, there is one dot.)

I am to find a formula for the nth triangular number.

The book says that each triangular number could be thought of as half the area of a rectangle whose width is the same as the triangle number, and it's height is n+1. So if n=2, the box is thought of as 2 units wide and 3 units tall, for a total of 6 units.

It also says that the formula for this problem is:

S-1/2(Width)(Length)=1/2(n)(n+1)

I have no idea how one would arrive at such an explanation for a pattern of said triangular numbers, nor how one would arrive at such a formula.

Any help on the correct way to solve a formula such as this and how to find the formula would be most appreciated.

Thanks a lot,

Rocker1414