Task

Find and display the sum of elements that are below the main diagonal of a matrix.

The matrix should be a square matrix.



 ───   Matrix to be used:   ───


     [[1,3,7,8,10],
      [2,4,16,14,4],
      [3,1,9,18,11],
      [12,14,17,18,20],
      [7,1,3,9,5]] 



 
see "working..." + nl
see "Sum of elements below main diagonal of matrix:" + nl
diag = [[1,3,7,8,10],
        [2,4,16,14,4],
        [3,1,9,18,11],
        [12,14,17,18,20],
        [7,1,3,9,5]]
 
lenDiag = len(diag)
ind = lenDiag
sumDiag = 0
 
for n=1 to lenDiag
    for m=1 to lenDiag-ind
        sumDiag += diag[n][m]
    next
    ind--
next
 
see "" + sumDiag + nl
see "done..." + nl
 