Build a c program used for calculations with Matrices

Write a program for performing calculation operations with matrices.

Before performing a mathematical operation, it is necessary to check whether the operation can be performed,
(eg whether the dimensions of the matrices match).

The program must enable:
Entering the desired number of matrices (you can limit the maximum number in the program).
Entered matrices are called by specifying the serial number. "R" specifies the result matrix of the previous operation.
Selecting and performing a mathematical operation:
Addition
Subtraction
Multiplication by a constant
Multiplication

Determining and printing the matrix type:
Unit - all elements are 0, except the elements on the main diagonal, which have a value of 1
Diagonal - all elements are 0, except elements on the main diagonal which have a value of != 0
Upper triangular - all elements below the main diagonal have a value of 0
Lower triangular - all elements above the main diagonal have a value of 0
The rest
Print the matrix on the screen