# C Program to Find Sum of Lower Triangle Matrix

In this tutorial, i am going to show you how to find sum of lower triangle matrix in c programs.

## Algorithm to Find Sum of Lower Triangle Matrix

Follow the below given algorithm to write a program to find or calculate sum of lower triangle matrix; as follows:

1. Start program.
2. Declare an M*N 2D array.
3. Initialize the array.
4. If the number of rows and columns are not equal then it is not possible to display the sum of the elements of the lower triangle.
5. If the number of rows is equal to the number of columns, then proceed for the calculation of lower triangular elements.
6. Using two for loops traverse through the elements.
7. If (i>=j), then add all the elements.
8. Display the final result.
9. Stop program.

## C Program to Find Sum of Lower Triangle Matrix

```#include<stdio.h>

int main()
{
int i, j, rows, columns, a, Sum = 0;

printf("\n Please Enter Number of rows and columns  :  ");
scanf("%d %d", &i, &j);

printf("\n Please Enter the Matrix Elements \n");
for(rows = 0; rows < i; rows++)
{
for(columns = 0;columns < j;columns++)
{
scanf("%d", &a[rows][columns]);
}
}

for(rows = 0; rows < i; rows++)
{
for(columns = 0; columns < j; columns++)
{
if(rows > columns)
{
Sum = Sum + a[rows][columns];
}
}
}

printf("\n The Sum of Lower Triangle Matrix = %d", Sum);
return 0;
}```

The result of the above c program; as follows:

```Please Enter Number of rows and columns  :  3 3