C program to calculate sum of elements of lower triangle of a n*n matrix.

Write a ‘C’ program to calculate sum of elements of lower triangle of a n*n matrix.

#include<stdio.h>
#include<conio.h>
void main()
{
int a[3][3],i,j,sum=0;
clrscr();
printf("enter the matrix element");
for(i=0;i<=2;i++)
{
for(j=0;j<=2;j++)
{
scanf("%d",&a[i][j]);
}
}
for(i=0;i<=2;i++)
{
for(j=0;j<=2;j++)
{
if(i>j)
{
sum=sum+a[i][j];
}
}
}
printf("%d\n",sum);
getch();
}