**i'm stuck on a homework assignment that I wasn't there for yesterday and I need help on how to do it.**

Dimensions of a matrix refer to the number of rows and number of columns

Matrix Dimension = rows x columns

1 2 3

4 5 6

7 8 9

1 2 3

The matrix above has 4 rows (horizontal) and 3 columns (vertical) so it is a 4 x 3 matrix.