A matrix that has the same number of rows and columns.
Example
This is a 3 × 3 matrix : \(\begin{pmatrix}1 & 3 & –5\\3 & 2 & 8\\6 & –4 & –3\end{pmatrix}\)
This is a 3 × 3 matrix : \(\begin{pmatrix}1 & 3 & –5\\3 & 2 & 8\\6 & –4 & –3\end{pmatrix}\)