Order or Size of Matrix

The order or size of a matrix is the number of rows and the number of columns that are present in a matrix.

For example, order of A is 3 ×2 (read as 3-by-2) and order of B is 3 ×3 (read as 3-by-3).

A matrix A of order m × n can be represented as

A = [a_ij]_m×n

The element a_ij belongs to i^th row and the j^th column, i being the row index and j being the column index.