TRY from all the ANGLES!!

The no. of triangles can be obtained by applying any of the two formulas mentioned below:

METHOD 1:

n(∆) =(floor(n x (n+2) x (2n+1))/8)

n(∆) = floor(111 X 113 X 223)/8

n(∆) = floor(2797089)/8

n(∆) = floor(349636.125)

n(∆) = 349636

If you are not familiar with floor function then for your information; floor function in maths is the largest integer less than or equal to the input.

METHOD 2:

If $n$ is even, $\displaystyle c_n = \frac{1}{8}n(n+2)(2n+1)$ .

If $n$ is odd, $\displaystyle c_n = \frac{1}{8}\left[n(n+2)(2n+1)-1\right]$