2ndtriangularnumber

<-- Enter triangular number statement
  

Calculate triangular number 2

The formula for triangular number n is as follows
Tn  =  n(n + 1)
  2

Given n = 2, we have:
T2  =  2(2 + 1)
  2

T2  =  2(3)
  2

T2  =  6
  2

T2 = 3