Dimesions Of a Matrix

To find the dimensions of the matrix, you need to count how many columns and rows there are. 

The rows are the numbers going horizantally.

 

The columns are the numbers going vertically.

 For the example below, there are two rows and three columns. So the dimensions would be written 2 x 3. The dimension format will always be written ROW x COLUMN.

 For the matrix below, the dimensions are 3 x 3. This matrix would also be classified as a square matrix, since the number of rows and columns are the same.

The matrix below has the dimensions 3 x 3. This matrix is called an identity matrix, because the numbers going across the diagonal is 1.