Figurate Numbers
From I2008
|
Square Numbers |
n^2 |
|
Rectangular Numbers |
n(n+1) |
|
Triangular Numbers |
n(n+1)
|
[edit] Square Numbers
Square numbers are... well, squares.
They have the same width and height.
If we were to picture it using dots, it would look like this:
Since they have the same width and height, the formula for square numbers is n^2 (n-squared).
[edit] Rectangular Numbers
They are rectangular.
They have a different width and height, one is one unit higher than the other..
If we were to picture it using dots, it would look like this:
Since one side is one unit higher than the other, the formula for rectangular numbers is n(n+1) or n^2+n.
[edit] Trianguluar Numbers
They are triangular.
They are half each rectangular number.
If we were to picture it using dots, it would look like this:
Since they are half rectangular numbers, the formula for triangular numbers is n(n+1) [OVER] 2 or n^2+n [OVER] 2.
