# How do I find the determinant of a matrix using row echelon form?

##### 1 Answer
Sep 5, 2014

I will assume that you can reduce a matrix to row echelon form to get the above matrix. This is also known as an upper triangular matrix.

Calculating the determinant is simple from here and it doesn't matter what the size of the matrix is. The determinant is simply the product of the diagonal, in this case:

${a}_{11} \cdot {a}_{22} \cdot {a}_{33} \cdot {a}_{44}$

Remember that you can only calculate the determinant for square matrices.