8thtriangularnumber

<-- Enter triangular number statement
  

Calculate triangular number 8

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

Given n = 8, we have:
T8  =  8(8 + 1)
  2

T8  =  8(9)
  2

T8  =  72
  2

T8 = 36