Upper Triangular Matrix/Examples/m greater than n

Example of Upper Triangular Matrix

An upper triangular matrix of order $m \times n$ such that $m > n$:

$\mathbf U = \begin{bmatrix} a_{11} & a_{12} & a_{13} & \cdots & a_{1, n - 1} & a_{1n} \\ 0 & a_{22} & a_{23} & \cdots & a_{2, n - 1} & a_{2n} \\ 0 & 0 & a_{33} & \cdots & a_{3, n - 1} & a_{3n} \\ \vdots & \vdots & \vdots & \ddots & \vdots & \vdots \\ 0 & 0 & 0 & \cdots & a_{n - 1, n - 1} & a_{n - 1, n} \\ 0 & 0 & 0 & \cdots & 0 & a_{nn} \\ 0 & 0 & 0 & \cdots & 0 & 0 \\ \vdots & \vdots & \vdots & \ddots & \vdots & \vdots \\ 0 & 0 & 0 & \cdots & 0 & 0 \\ 0 & 0 & 0 & \cdots & 0 & 0 \\ \end{bmatrix}$