Matrix Dimensions

Square Matrices

A Square Matrix is a matrix with the same number of rows and columns.

An n-by-n matrix is known as a square matrix of order n.

A 2-by-2 matrix (Square matrix of order 2):

A 4-by-4 matrix (Square matrix of order 4):

Diagonal Matrices

A Diagonal Matrix has values on the diagonal entries, and zero on the rest:

The Identity Matrix

The Identity Matrix has 1 on the diagonal and 0 on the rest.

This is the matrix equivalent of 1. The symbol is I.

If you multiply any matrix with the identity matrix, the result equals the original.

The Zero Matrix