Triangular numbers can be represented with equilateral triangles formed by dots. the first five triangular numbers are 1, 3, 6, 10, and 15. is there a direct variation between a triangular number and its position in the sequence? explain your reasoning.

Nth triangular number = n* (n+1) / 2
Basically, input the triangular number's  position in the sequence (for example four) then input the number position into the equation and you get the triangular number's value.
Example:
4 * (5/2) = 10
So, the 4th triangular number has a value of 10.