How to Find the nth Triangular Number

The video tutorial explains how to find the NTH triangular number by visualizing dots as right-angled triangles and then forming rectangles. It introduces a formula to calculate triangular numbers and provides an example with n=4. The video concludes with practice questions for viewers to solve.

For the 4th triangular number, what value of N is used in the example?

What is the relationship between the number of dots in the triangle and the rectangle?