Observe the matrix; the matrix has 3 rows and 3 columns.

So, the dimensions of matrix are .

The determinant of a matrix is called third-order determinant.

Evaluate the third-order determinant using expansion by minors method

Find the determinant using third-order determinant definition.

Evaluate the determinants using second-order determinant definition.

             (Simplify)

The determinant is 

.