Triangular numbers

Project work

2. A triangular number is the number of dots in an equilateral triangle with dots uniformly filled.
For example, the three dots may form a triangle and hence 3 is a triangular number. The n-th
triangular number is the number of dots of a triangle on the side of the n points.
Equivalently, a triangular number is the addition of the first n positive integers from 1 to n.
[2]

3. [4] [5]

4. [5]
The handshake problem:
“If a group of n people greet each other, the total number of handsheaks will be triangular number”.
To make a fully connected network of PC. The nodes of the network are connected to more than one
other node in the network with a point-to-point link
This is the triangular number of the internet nodes.

5. [1] http://en.wikipedia.org/wiki/Triangular_number
[2] http://www.shyamsundergupta.com/triangle.htm
[3] https://mathblag.wordpress.com/2012/06/23/a-product-rule-for-triangular-numbers/
[4] http://unurthed.com/2007/11/21/polygonal-numbers-and-a-slice-of-pie/
[5] http://en.wikipedia.org/wiki/Network_topology#Mesh