Here's a C program to add the given two matrices with proper explanation and output. This program uses Multidimensional Arrays, Nested Loops and For Loops.

# include <stdio.h> # include <conio.h> void main() { int mata[10][10], matb[10][10], matc[10][10] ; int i, j, row, col ; clrscr() ; printf("Enter the order of the matrix : ") ; scanf("%d %d", &row, &col) ; printf("\nEnter the elements of first matrix : \n\n") ; for(i = 0 ; i < row ; i++) for(j = 0 ; j < col ; j++) scanf("%d", &mata[i][j]) ; printf("\nEnter the elements of second matrix : \n\n") ; for(i = 0 ; i < row ; i++) for(j = 0 ; j < col ; j++) scanf("%d", &matb[i][j]) ; for(i = 0 ; i < row ; i++) for(j = 0 ; j < col ; j++) matc[i][j] = mata[i][j] + matb[i][j] ; printf("\nThe resultant matrix is : \n\n") ; for(i = 0 ; i < row ; i++) { for(j = 0 ; j < col ; j++) { printf("%d \t", matc[i][j]) ; } printf("\n") ; } getch(); }

**Output of above program**

Enter the order of the matrix : 3 3

Enter the elements of first matrix :

1 3 5

7 9 11

13 15 17

Enter the elements of second matrix :

2 4 6

8 10 12

14 16 18

The resultant matrix is :

3 7 11

15 19 23

27 31 35

**Explanation of above program**

In this program, we have three square matrices

*mata, matb and matc*all of maximum size 10 x 10. The matrices*mata*and*matb*are the two matrices whose sum we wish to calculate and matrix*matc*contains the sum of*mata*and*matb.*The variables i and j are the loop variables that corresponds to the row and column of the matrix respectively. The variables*row*and*col*contain the row and column i.e. the order of the matrix.
First, the program prompts the user to enter the order of the matrix. Since two matrices can be added only when they are of the same order, so, we need to enter the order only once. After getting the order of the matrices using first two Nested For Loops the program populates the matrices

*mata*and*matb.*
The sum of two matrices

*mata*and*matb is*calculated using the third nested for loop and then stored in the matrix*matc.*Using the fourth and last nested for loop, the values in the matrix*matc*i.e. the sum of the given matrices is printed on the screen.Also look at:C Program to Subtract the Given Two Matrices