A square matrix A is said to be a symmetric matrix if
A=AT
We have discussed that a square matrix A is called as symmetric matrix if the matrix is equal to its transpose.
Eg. Lets take a 2 × 2 matrix [1222]
If we take its transpose the transpose matrix will be [1222] which is equal to the original matrix itself. So these type of matrices which remain same after taking the transpose are called as symmetric matrices.