write a c programs to find the trace of a given matrix.

To find the trace of a given matrix, you can follow these steps in a C program:

1. Declare variables to store the size of the matrix and the trace.
2. Take input from the user for the size of the matrix.
3. Declare a 2D array to hold the matrix elements.
4. Take input from the user for the matrix elements.
5. Calculate the trace of the matrix by summing up the diagonal elements.
6. Display the trace.

Here's an example C program that implements the above steps:

```c
#include <stdio.h>

int main() {
int i, j, size, trace = 0;

printf("Enter the size of the matrix: ");
scanf("%d", &size);

int matrix[size][size];

printf("Enter the matrix elements:\n");
for (i = 0; i < size; i++) {
for (j = 0; j < size; j++) {
scanf("%d", &matrix[i][j]);
}
}

for (i = 0; i < size; i++) {
trace += matrix[i][i];
}

printf("Trace of the matrix: %d\n", trace);

return 0;
}
```

In this program, we take input for the size of the matrix and then create a 2D array using the `size` variable. We then use nested loops to take input for each element of the matrix.

Next, we calculate the trace by iterating through the diagonal elements (where row index is equal to the column index) and summing them up.

Finally, we display the trace to the user.

You can run the program and input the matrix elements to find the trace of the given matrix.