Here, We’ll learn to write a program to check whether the given matrix is upper triangular or not in C programming language.

**Upper Triangular Matrix: **A matrix is known as an upper triangular matrix if all the values below diagonal are 0.

###### Source: https://commons.wikimedia.org/wiki/File:Triangular_matrix.svg

**Code:**

```
#include<stdio.h>
#include<conio.h>
void main()
{
int a[10][10],i,j,n,flag;
clrscr();
printf("Enter the order of the matrix : ");
scanf("%d",&n);
printf("Enter matrix elements :\n ");
for(i=0;i<=n-1;i++)
{
for(j=0;j<=n-1;j++)
{
printf("i=%dj=%d\n",i,j);
scanf("%d",&a[i][j]);
}
}
flag = 1;
for(i=0;i<=n-2;i++)
{
for(j=i+1;j<=n;j++)
{
if(a[i][j] !=0) flag = 0;
break;
}
}
if(flag)
printf("Upper triangle matrix ");
else
printf("Not a Upper triangle matrix");
getch();
}
```